The purpose of this research was to extent personality trait words from Koujien as preparatory investigation in a lexical approach to the big five; to evaluate their appropriateness as personality trait words; and finally to provide researchers with a collection of basis personality trait words. In Study 1. four psychology-major students, under explicit rules of extraction, collected 950 words from the dictionary. In Study 2, three psychology-major students scrutinized the collection, and deleted 14 words that they judged inappropriate. Also, about 300 words each were allocated, and 341 undergraduates made judgment to cross out words that were not suitable for personality description. Assuming less than 20% fir the cross-out rate, 752 words were left. In Study 3, 125 undergraduates crossed out 174 words of the Tsuji list (2001), and 25 of the Aoki list (1971a), leaving 157 words of the former list and 23 of the latter. With the three studies, 536 nouns, 144 adjectives, 110 verbs, and 107 compound words, 934 in total, were collected.

Key words: lexical study, Koujien, big five