The purpose of this study was to investigate the word familiarity by visual and auditory presentation in Japanese as a second language. 299 Kanji-words and 22 Hiragana-words were adopted as materials in the experiment. The results showed that word familiarity of kanji (Chinese character) by visual presentation was different from that by auditory presentation. The results also indicated that the difference was not observed in relation to word familiarity of Hiragana. It was suggested that in auditory presentation experiments, we should use the auditory familiarity.