There are many tongjiazi in the Chinese versions of Buddhist Scriptures. They have distinctive characteristics, and are closely related to the study of the words in translated Buddhist scriptures. Studying tongjiazi is valuable and meaningful for the study of the words in the translated Buddhist scriptures, which will be discussed in the following five aspects: First, it examines the meanings of the words and helps interpret the sutras correctly. For many difficult words in Chinese Buddhist translations, it is difficult to find an explanation if only its literal meaning is examined, but it is possible to analyze tongjiazi and find the original word and then interpret the meaning of sutras correctly. For example, the “隤” in“云隤” is the interchangeable word of “队”, “刬” in the “刬其身” is the interchangeable word of “丳”, and “落” in the “落治” should be read as “〖XC各.tif,JZ〗”. So the meanings of “隤”,“刬”,“落” can be explained correctly with a background knowledge of their respective interchangeable word. Second, it provides new ideas and evidence for the existing research and offers a new interpretation of the Buddhist scriptures. Some researches on the words of Buddhist translations are inadequate literal interpretations without truly understanding the meanings, or fail to explain the development of the meanings. Analyzing interchangeable words can be a way to clarify the misinterpretation and to elucidate the reasons for the correct meanings. For example, “脯” in “脯煮” should be read as“缹”; “脯煮” is equivalent to ″boiled″ , and doesnt mean ″be dried and boiled″ as was explained by Prof. KARASHIMA Seishi. Furthermore, words such as “疽尅”,“诱訹”and “牒” get new interpretations from the interchangeable words in the text . Third, it helps identify the arbitrary changes to the texts of Buddhist scriptures caused by the ignorance of the interchangeable word, and base the research of the words of Buddhist Sutras on the actual texts. Interchangeable words often change with the times. A good knowledge of the interchangeable words in the Chinese Buddhist translations helps discern and correct the mistakes in the arbitrary changes so that the research of the words of Buddhist translations can be based on the original texts. Fourth, it helps us to get out of the dilemma of the usage of words and date the words accurately. The form of Chinese vocabulary is complicated and the words in Buddhist translations are no exception. This impedes the dating work. Analyzing interchangeable words gives us a better understanding of the diversity of the forms of the words in Buddhist translations, and distinguishes ″character″ and ″word″ so that the words are dated accurately. At the same time, the dating of the words also benefits the dating of a certain translated version of Buddhist Sutra. Fifth, it helps identify the written form of the words and thus avoid mistakes when incorporating certain lost lexical items into dictionaries. Currently, using Buddhist texts to supplement the lost items into Chinese Dictionary is a focus in the study of words and expressions used in the Buddhist Scriptures. However, some words which were not included in the dictionaries have been mistaken as lost or error words. Studying the interchangeable words in Chinese Buddhist translations is helpful in distinguishing such words and their written forms.