diff --git a/csst_mci_sim/csst_mci_sim.py b/csst_mci_sim/csst_mci_sim.py
index 5d36ae516a1ee22aa6a09f001c2c0ab7baab0d7c..69df32c536d654ad70355b4b970f67205e415112 100644
--- a/csst_mci_sim/csst_mci_sim.py
+++ b/csst_mci_sim/csst_mci_sim.py
@@ -2088,6 +2088,7 @@ class MCIsimulator():
                 cx0,cy0=centroid(stamp_img.array)
                 
                 if self.appFatt : 
+                    self.log.info('begin appfat ........')
                     
                 ### apply treering and bright fatter and diffusion;                        
                     SimpleTreeRing = galsim.SiliconSensor().simple_treerings(amplitude=self.information['treering'])                  
@@ -2110,6 +2111,9 @@ class MCIsimulator():
                     photons=galsim.PhotonArray.makeFromImage(image, max_flux=1.0)
                     
                     cx0,cy0=centroid(image.array)
+                    
+                    
+                    self.log.info('finish appfat ........')
                         
                 ############################################
                 ############################################