An experiment was carried out to investigate the level of difficulty in auditory recognition of four types of words (Chinese-Japanese cognates, non-cognates, hiragana-words, and katakana-words) in Taiwanese learners. All subjects were learning Japanese as a second language in Japan and were in advanced class. In this experiment, the meaning decision task was used, and the correct response time was measured. The results were as follows: (1) the response time of Chinese-Japanese cognates was longer than that of other words, and (2) the error rate of cognates was higher than that of non-cognates and katakana-words. It was suggested that the processing of meaning of cognates was slower than the processing of non-cognates, hiragana-words, and katakana-words in Taiwanese learners. These results were discussed based on the mental lexicon model in Chinese-Japanese bilinguals.