In this paper it was examined at the center of the vocabulary of Japanese textbook index entry of the high school from secondary education curriculum until 2009 revised curriculum. Its main results were as follows. (1)becomes to appear the difference between the number of vocabulary based on changes in the curriculum by educational goals, the number of vocabulary according orders from the secondary curriculum increases it is possible to know that the decreased slightly. (2)it was possible to find the different number of words according to the curriculum and the telling number of words more numerous than the first volume except for several degrees. (3)vocabulary in spite of the limited vocabulary of each was presented curriculum to the item, another difference is textbook, the number of units and the textbook by the number of pages of the curriculum, each including how to create author vocabulary and vocabulary list textbooks I because different. (4)common vocabulary in a whole different number of words 14,395 words of secondary education 2009 revised curriculum ‘Japanese Ⅰ`` in textbooks index vocabulary from the course in a total of 22 words, the common vocabulary of the entire educational process is fairly it was possible to know that small. (5)secondary education very low lexical similarity of from eight curriculum until 2009 revised curriculum from the program, the percentage of vocabulary common level is occupied by low as the entire vocabulary was high.