diff --git a/EduNLP/Formula/Formula.py b/EduNLP/Formula/Formula.py
index 71038480..77e5f7d0 100644
--- a/EduNLP/Formula/Formula.py
+++ b/EduNLP/Formula/Formula.py
@@ -17,6 +17,18 @@ class Formula(object):
     """
     The part transform a formula to the parsed abstracted syntax tree.
 
+    Attributes
+    ------------
+    ast
+        show all ast details
+    elements
+        just show elements' id, type, text and role
+    ast_graph
+        draw a ast graph
+    to_str
+    resetable
+        return bool
+
     Parameters
     ----------
     formula: str or List[Dict]
@@ -129,6 +141,16 @@ class FormulaGroup(object):
     """
     The part transform a group of formula to the parsed abstracted syntax forest.
 
+    Attributes
+    ------------
+    to_str
+    ast
+        show all ast details
+    elements
+        just show elements' id, type, text and role
+    ast_graph
+        draw a ast graph
+
     Parameters
     ----------
     formula: str or List[Dict] or List[Formula]
diff --git a/EduNLP/SIF/parser/parser.py b/EduNLP/SIF/parser/parser.py
index cd2bf65e..471bb450 100644
--- a/EduNLP/SIF/parser/parser.py
+++ b/EduNLP/SIF/parser/parser.py
@@ -3,7 +3,18 @@
 
 
 class Parser:
-    """initial data and special variable"""
+    """
+    initial data and special variable
+
+    Attributes
+    ----------
+    get_token
+        Get different elements in the item.
+    txt_list
+        show txt list
+    description_list
+        use Parser to process and describe the txt
+    """
     def __init__(self, data):
         self.lookahead = 0
         self.head = 0
diff --git a/EduNLP/SIF/segment/segment.py b/EduNLP/SIF/segment/segment.py
index 2bbefdca..7e9ed5ed 100644
--- a/EduNLP/SIF/segment/segment.py
+++ b/EduNLP/SIF/segment/segment.py
@@ -82,6 +82,23 @@ class SepSegment(str):
 class SegmentList(object):
     """
 
+    Attributes
+    ----------
+    segments
+        show all segments
+    text_segments
+        show text segments
+    formula_segments
+        show formula segments
+    figure_segments
+        show figure sements
+    ques_mark_segments
+        show question mark segments
+    tag_segments
+        show tag segments
+    describe
+        show number of each elements
+
     Parameters
     ----------
     item
diff --git a/EduNLP/SIF/tokenization/tokenization.py b/EduNLP/SIF/tokenization/tokenization.py
index 53f6fe75..93eb61a1 100644
--- a/EduNLP/SIF/tokenization/tokenization.py
+++ b/EduNLP/SIF/tokenization/tokenization.py
@@ -26,7 +26,20 @@ class TokenList(object):
 
     Attributes
     -------------
-
+    tokens
+        show all tokens
+    text_tokens
+        show text tokens
+    formula_tokens
+        show formula tokens
+    figure_tokens
+        show figure tokens
+    ques_mark_tokens
+        show question mark tokens
+    tag_tokens
+        show tag tokens
+    describe
+        show number of each elements
     """
     def __init__(self, segment_list: SegmentList, text_params=None, formula_params=None, figure_params=None):
         self._tokens = []