diff --git a/tests/test_SpecDisperse.py b/tests/test_SpecDisperse.py
index e3ed429028a2c97d94a1b57f8b07a3755a493769..6893b74da88e658e4a999872ba3d6c839c90148f 100644
--- a/tests/test_SpecDisperse.py
+++ b/tests/test_SpecDisperse.py
@@ -1,3 +1,8 @@
+#
+#need add environment parameter  TEST_HOME, link to "testData/"
+#linx and mac can run as follow, need modify the name of file directory
+#export TEST_HOME=/Users/zhangxin/Work/SlitlessSim/CSST_SIM/CSST_develop/csst-simulation/tests/testData
+#
 import unittest
 from ObservationSim.MockObject.SpecDisperser import rotate90, SpecDisperser
 
diff --git a/tests/test_Straylight.py b/tests/test_Straylight.py
index 323fe31cd5fb65ea933405bf14514a98160e3068..9cba6e1e3d29587158f9b9d2caece360fa604f85 100644
--- a/tests/test_Straylight.py
+++ b/tests/test_Straylight.py
@@ -1,3 +1,8 @@
+#
+#need add environment parameter  TEST_HOME, link to "testData/"
+#linx and mac can run as follow, need modify the name of file directory
+#export TEST_HOME=/Users/zhangxin/Work/SlitlessSim/CSST_SIM/CSST_develop/csst-simulation/tests/testData
+#
 import unittest
 from ObservationSim.Straylight import Straylight