diff --git a/Absorption-Imaging-Class.md b/Absorption-Imaging-Class.md
index f1c4dfc..a522a77 100644
--- a/Absorption-Imaging-Class.md
+++ b/Absorption-Imaging-Class.md
@@ -8,6 +8,12 @@ This is a class for getting data of absorption imaging form three standard image
 | absorption_imaging.get_atom_number | Calculte the atom number accoring to the absorption imaging |
 | absorption_imaging.plot_result | Ploting the result |
 
-### absorption_imaging.\_\_init\_\_
-dylab.absorption_imaging(data_path, camera_orientation, camera_label, transition=None, camera=None, detuning=None, intensity=None)
-* data_path
\ No newline at end of file
+## absorption_imaging.\_\_init\_\_
+> dylab.absorption_imaging(data_path, camera_orientation, camera_label, transition=None, camera=None, detuning=None, intensity=None)
+
+Initialization function of the absorption imaging class. The path of those three standard pictures should be "camera_orientation\camera_label". The defult name of them are "atoms", "background" and "dark". If you would like to change their name for different configuration, plase use function **absorption_imaging.set_image_name()**
+
+### Parameters:
+* **data_path** *(unknown, necessary)*: The path of hdf5 file provided by lyse moduel in LabScript.
+* **camera_orientation** *(string, necessary)*: Name of the camare group in hdf5 file.
+* **camera_label** *(string, necessary)*: Name of the imaging group in hdf5 file.
\ No newline at end of file