diff --git a/R/CST_QuantileMapping.R b/R/CST_QuantileMapping.R
index 0ac443ba519c32dac843f588ab1bf20ae3900ee3..92b7ac038161d037ab3b9409bf42c97dd3376aa1 100644
--- a/R/CST_QuantileMapping.R
+++ b/R/CST_QuantileMapping.R
@@ -14,8 +14,9 @@
 #'@param sdate_dim A character string indicating the dimension name in which 
 #'  cross-validation would be applied when exp_cor is not provided. 'sdate' by 
 #'  default.
-#'@param memb_dim A character string indicating the dimension name where 
-#'  ensemble members are stored in the experimental arrays. 'member' by default.
+#'@param memb_dim A character string indicating the dimension name where
+#'  ensemble members are stored in the experimental arrays. It can be NULL if 
+#'  there is no ensemble member dimension. It is set as 'member' by default.
 #'@param window_dim A character string indicating the dimension name where 
 #'  samples have been stored. It can be NULL (default) in case all samples are 
 #'  used. 
@@ -106,8 +107,8 @@ CST_QuantileMapping <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate',
 #'  cross-validation would be applied when exp_cor is not provided. 'sdate' by
 #'  default.
 #'@param memb_dim A character string indicating the dimension name where
-#'  ensemble members are stored in the experimental arrays. 'member' by 
-#'  default. 
+#'  ensemble members are stored in the experimental arrays. It can be NULL if 
+#'  there is no ensemble member dimension. It is set as 'member' by default.
 #'@param window_dim A character string indicating the dimension name where 
 #'  samples have been stored. It can be NULL (default) in case all samples are
 #'  used. 
@@ -183,30 +184,28 @@ QuantileMapping <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate',
          "'PTF', 'DIST', 'RQUANT', 'QUANT', 'SSPLIN'.")
   }
   # memb_dim
-  if (!all(memb_dim %in% obsdims)) {
-    obs <- InsertDim(obs, posdim = 1, lendim = 1,
-                     name = memb_dim[!(memb_dim %in% obsdims)])
-  }
-  if (any(!memb_dim %in% expdims)) {
-    stop("Parameter 'memb_dim' is not found in 'exp' dimensions.")
+  if (is.null(memb_dim)) {
+    remove_member <- TRUE
+    memb_dim <- "temp_memb_dim"
+    exp <- InsertDim(exp, posdim = 1, lendim = 1, name = "temp_memb_dim")
+    obs <- InsertDim(obs, posdim = 1, lendim = 1, name = "temp_memb_dim")
+    obsdims <- names(dim(obs))
+    expdims <- names(dim(exp))
+    if (!is.null(exp_cor)) {
+      exp_cor <- InsertDim(exp_cor, posdim = 1, lendim = 1, name = "temp_memb_dim")
+    }
+  } else {
+    remove_member <- FALSE
+    if (!all(memb_dim %in% obsdims)) {
+      obs <- InsertDim(obs, posdim = 1, lendim = 1,
+                       name = memb_dim[!(memb_dim %in% obsdims)])
+      obsdims <- names(dim(obs))
+    }
+    if (any(!memb_dim %in% expdims)) {
+      stop(paste0("Parameter 'memb_dim' is not found in 'exp' dimensions. ", 
+                  "Set it as NULL if there is no member dimension."))
+    }
   }
-
-  # if (is.null(memb_dim)) {
-  #   remove_member <- TRUE
-  #   exp <- InsertDim(exp, posdim = 1, lendim = 1, name = 'member')
-  #   obs <- InsertDim(obs, posdim = 1, lendim = 1, name = 'member')
-  #   memb_dim <- 'member'
-  # } else {
-  #   remove_member <- FALSE
-  #   if (!all(memb_dim %in% obsdims)) {
-  #     obs <- InsertDim(obs, posdim = 1, lendim = 1,
-  #                     name = memb_dim[!(memb_dim %in% obsdims)])
-  #   }
-  #   if (any(!memb_dim %in% expdims)) {
-  #     stop("Parameter 'memb_dim' is not found in 'exp' dimensions.")
-  #   }
-  # }
-  
   sample_dims <- c(memb_dim, sdate_dim)
   # window_dim
   if (!is.null(window_dim)) {
@@ -232,7 +231,6 @@ QuantileMapping <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate',
   }
 
   ###############################
-
   if (!is.null(exp_cor)) {
     qmaped <- Apply(list(exp, obs, exp_cor), target_dims = sample_dims, 
                     fun = .qmapcor, method = method, sdate_dim = sdate_dim,
@@ -244,14 +242,16 @@ QuantileMapping <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate',
                     sdate_dim = sdate_dim, na.rm = na.rm, ...,                
                     ncores = ncores)$output1
   }
-  # if (remove_member) {
-  #   dim(qmaped) <- dim(qmaped)[-which(names(dim(qmaped)) == 'member')]
-  # }
+  # remove added 'temp_memb_dim'
+  if (remove_member) {
+    dim(qmaped) <- dim(qmaped)[-which(names(dim(qmaped)) == "temp_memb_dim")]
+  }
+
   return(qmaped)
 }
 
-.qmapcor <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate', method = 'QUANT', 
-                     na.rm = FALSE, ...) {
+.qmapcor <- function(exp, obs, exp_cor = NULL, sdate_dim = 'sdate', 
+                     method = 'QUANT', na.rm = FALSE, ...) {
 
   # exp: [memb (+ window), sdate]
   # obs: [memb (+ window), sdate] 
diff --git a/man/CST_QuantileMapping.Rd b/man/CST_QuantileMapping.Rd
index fc77d3bfac261bf56994330a8045a3a934e284ad..0ca3423f9d64002f088417482ca195593cb8bdff 100644
--- a/man/CST_QuantileMapping.Rd
+++ b/man/CST_QuantileMapping.Rd
@@ -30,8 +30,9 @@ is applied in object 'exp'.}
 cross-validation would be applied when exp_cor is not provided. 'sdate' by 
 default.}
 
-\item{memb_dim}{A character string indicating the dimension name where 
-ensemble members are stored in the experimental arrays. 'member' by default.}
+\item{memb_dim}{A character string indicating the dimension name where
+ensemble members are stored in the experimental arrays. It can be NULL if 
+there is no ensemble member dimension. It is set as 'member' by default.}
 
 \item{window_dim}{A character string indicating the dimension name where 
 samples have been stored. It can be NULL (default) in case all samples are 
diff --git a/man/QuantileMapping.Rd b/man/QuantileMapping.Rd
index c4c29e7f47d2121b36f65d6e47cc33a20457da9f..a1ff178de2c0170e6b2a675bf7a9747beb0b4ff2 100644
--- a/man/QuantileMapping.Rd
+++ b/man/QuantileMapping.Rd
@@ -33,8 +33,8 @@ cross-validation would be applied when exp_cor is not provided. 'sdate' by
 default.}
 
 \item{memb_dim}{A character string indicating the dimension name where
-ensemble members are stored in the experimental arrays. 'member' by 
-default.}
+ensemble members are stored in the experimental arrays. It can be NULL if 
+there is no ensemble member dimension. It is set as 'member' by default.}
 
 \item{window_dim}{A character string indicating the dimension name where 
 samples have been stored. It can be NULL (default) in case all samples are
diff --git a/tests/testthat/test-CST_QuantileMapping.R b/tests/testthat/test-CST_QuantileMapping.R
index 0b2890f3eb90d370d381ad629416f82826640ff7..a086ab93d3de7f2f6a4187bec54b0c5e95596e9b 100644
--- a/tests/testthat/test-CST_QuantileMapping.R
+++ b/tests/testthat/test-CST_QuantileMapping.R
@@ -99,14 +99,15 @@ exp_cor6_1$data <- ClimProjDiags::Subset(exp_cor6_1$data, 'sdate', 1)
 exp_cor6_2 <- exp6
 exp_cor6_2$data <- ClimProjDiags::Subset(exp_cor6_2$data, 'member', 1:2)
 
-# # dat7
-# exp7 <- 1 : c(1 * 1 * 6 * 3 * 8 * 8)
-# dim(exp7) <- c(dataset = 1,  sdate = 6, ftime = 3,
-#                    lat = 8, lon = 8)
+# dat7
+exp7 <- 1 : c(1 * 1 * 6 * 3 * 4 * 4 * 2)
+dim(exp7) <- c(dataset = 1,  sdate = 6, ftime = 3,
+               lat = 4, lon = 4, member = 2)
 
-# obs7 <- 101 : c(100 + 1 * 1 * 6 * 3 * 8 * 8)
-# dim(obs7) <- c(dataset = 1, sdate = 6, ftime = 3,
-#                    lat = 8, lon = 8)
+obs7 <- 101 : c(100 + 1 * 1 * 6 * 3 * 4 * 4 * 2)
+dim(obs7) <- c(dataset = 1, sdate = 6, ftime = 3,
+               lat = 4, lon = 4, window = 2)
+exp_cor7 <- exp7 + 1
 
 ##############################################
 
@@ -129,7 +130,7 @@ test_that("1. Sanity checks", {
   expect_error(
     CST_QuantileMapping(exp = exp1, obs = obs1, exp_cor = 1),
     paste0("Parameter 'exp_cor' must be of the class 's2dv_cube', as output ",
-    "by CSTools::CST_Load.")
+           "by CSTools::CST_Load.")
   )
   # exp and obs
   expect_error(
@@ -235,9 +236,24 @@ test_that("4. dat6", {
 
 ##############################################
 
-# test_that("5. dat7", {
-#   expect_equal(
-#     dim(QuantileMapping(exp7, obs7, memb_dim = NULL)),
-#     c(sdate = 6, dataset = 1, ftime = 3, lat = 8, lon = 8)
-#   )
-# })
\ No newline at end of file
+test_that("5. dat7", {
+  expect_equal(
+    dim(QuantileMapping(exp7, obs7, memb_dim = NULL)),
+    c(sdate = 6, dataset = 1, ftime = 3, lat = 4, lon = 4, member = 2, window = 2)
+  )
+  # window_dim
+  expect_equal(
+    dim(QuantileMapping(exp7, obs7, memb_dim = NULL, window_dim = 'window')),
+    c(sdate = 6, dataset = 1, ftime = 3, lat = 4, lon = 4, member = 2)
+  )
+  # exp_cor
+  expect_equal(
+    dim(QuantileMapping(exp7, obs7, exp_cor7, memb_dim = NULL)),
+    c(sdate = 6, dataset = 1, ftime = 3, lat = 4, lon = 4, member = 2, window = 2)
+  )
+  expect_equal(
+    dim(QuantileMapping(exp7, obs7, exp_cor7, memb_dim = NULL, 
+        window_dim = 'window')),
+    c(sdate = 6, dataset = 1, ftime = 3, lat = 4, lon = 4, member = 2)
+  )
+})