An experimental study was carried out to investigate how Chinese students learning Japanese process two languages (native and second language), using picture-word category matching task. The participants were eight Chinese-speaking students learning Japanese as a second language in Japan. They were in the beginning class of Japanese and were preparing for the fourth level of The Japanese-Language Proficiency Test. Two types of words (similar and dissimilar Japanese words with Chinese words) were used in the experiment to examine how lexical representation is related with conceptual representation. The patterns of reaction times in Japanese condition suggested that there was no direct link between Japanese lexical representation and concept representation. The results also showed a possibility that an associative relationship of similar words between Japanese lexical representation and concept representation was different from that of dissimilar words. Some educational implications for a beginning class of Chinese students learning Japanese were led out based on these results.