The Dictionary of Chinese Variants Characters (《異體字字典》), compiled by Ministry of Education, has cited 62 philology books and 1242 practical literatures to collect 29892 standard characters and 76338 variant characters. There are 106230 characters in total in The Dictionary of Chinese Variants Characters (《異體字字典》). It is absolutely a large-scale work of Chinese characters. The Dictionary of Chinese Variants Characters (《異體字字典》) adopts the stratified method. All standard characters and variant characters are well-indexed by establishing links between every standard character and its variant(s). The same criteria of standard character is also adopted by The List of Commonly-used Characters ( 《常用字表》), The List of Less-commonly-used Characters (《不常用字表》) and The list of Rarely-used Characters (《疑难字表》). Meeting the criteria, 29528 characters are eligible. Furthermore, to satisfied the needs of practical use, additional 364 characters are also collected. Those “standard characters” and “variants”, in the dictionary, not created to be “standard” or “variant”. On the contrary, when a charater is defined as “the standard”, its remaining isomeric siblings would turn into “variants” spontaneously. Therefore, The definition of “variant” in the dictionary is : With the same nature and meanings, but different stracture and form to its standard counterpart. This article is about the criteria of standard character which adopted by The Dictionary of Chinese Variants Characters (《異體字字典》), and the association between a standard character and its variant(s).

“Mutually explanatory characters is to describe a concept without actualcharacter by the way of borrowing characters with the same pronunciation.” Said in Hsu Shen’ s(許慎) masterpiece “Shuo Wen JieZi.”(說文解字) Duan Yu-tsai(段玉裁)put more emphasis on the linkage of pronunciation of two characters. However, there are examples contradictory to Duan’s theory in his book. Here we can get conclusion through analysis of relative documents.