The purpose of this study was to investigate the processing of kanji words by Chinese learners of Japanese during reading of sentences in Japanese. In the experiment, we manipulated the contextual constraint (high vs. low) and the orthographical and phonological similarities of kanji words between Chinese and Japanese, and investigated the processing through oral translation task using moving window method. The experimental results indicate: (1) in high-constraint sentence condition, facilitatory effect of orthographical similarity was observed in the case of low phonological similarity words, and inhibitory effect of phonological similarity occurred in high orthographical similarity words; (2) in the low-constraint sentence condition, facilitatory eff ect of orthographical similarity was observed in both high and low phonological similarity words, and facilitatory eff ect of phonological similarity in low orthographical similarity words. In short, the constraint of sentences affects the level of activation of kanji words at sentence processing stage, thus leading to different effects of orthographical and phonological similarities of kanji words.