The present study investigated the lexical processing of Japanese Kanji-words in Japanese learners of Chinese by using a lexical decision task. In the experiment, intermediate learners were asked to perform a lexical decision task involving Japanese words and non-words in the pre-test. The target Japanese words were selected by manipulating the orthographical and phonological similarities with Chinese. In two weeks, the repeated words shadowing practices were executed 8 times 30 minutes each time. After the shadowing practices, the posttest has been carried out. Then the post-test is compared with the pre-test. The reaction time of high orthographical similarities was shortened than the pre-test. The results showed that in high orthographical similarities appeared significant difference. It is seen that promoting effect according to the high orthographic similarities in the state of auditory presentation. These suggest that through the shadowing practices Japanese orthographic representation and phonological representation consolidated in mental lexicon has become stronger.