Cognitive processing of visual word and effects of its context has been the crucial issues in psycholinguistics and cognitive psychology. In order to reveal the characters of behavior and its mechanism of Chinese word recognition in sentence context, methods incorporating eye tracking method and brain event-related potentials technology was used.The first investigation explored the role of orthography and phonology of Chinese word in lexical access when target word was presented separately in high constraint and low constraint sentence using eye tracking method. The results showed that: in different constraint sentence context, target words of different types have a different pattern on first fixation duration, gaze duration and total fixation duration. In addition, word frequency effects were not found in high constraint sentence context whereas the frequency effects were exhibited by gaze duration and total fixation duration in low constraint sentence context. The second investigation used ERP technology to clarify the time course of phonology in lexical access in high constraint sentence context. Three distinct ERP components such as P200, P300, and N400 were elicited in the experiment. The P200 and N400 were observed in response to change of orthography and phonology. Meanwhile, word frequency effects also exhibited on P200 and had a reversed frequency effects on N400. The third investigation conducted two eye tracking experiments to explore the role of sentence context and relative frequency of ambiguous Chinese word during lexical ambiguity resolution. According to the analysis of fixation time on target words and disambiguating information, it was found that: meanings of ambiguous word were accessed in order of their relative frequency in the neutral sentence context. However, in the biased sentence context, effects of relative frequency were not found at early of ambiguous word meaning access. The fourth investigation applied ERP technology to examine the role of sentence context and the time course of activation of different meaning during lexical ambiguity resolution. According to the changes of N400 which was measured to target word, we found that different meanings of ambiguous word were activated at early of lexical access.All of the results suggest that: (1) The constraint of sentence context have impact on the role of orthography and phonology of Chinese word in lexical access. In the higher constraint sentence context, orthography plays a crucial role at early of lexical access whereas both orthography and phonology play an early and dominant role in the lower constraint sentence context. At the later stage of lexical access, phonology facilitates the integrating process. (2) Context interacts with word frequency. The interaction between context and word frequency occurs at post-lexical stage in the higher constraint sentence context whereas the interaction was found at pre-lexical stage in the lower constraint sentence context. (3) Lexical ambiguity resolution is in order of relative frequency in neutral sentence context, however, the process of lexical ambiguity resolution is delayed in the biased sentence context. Both of the different meanings of ambiguous word are activated at the early stage of meaning access and support the modular points of view. (4) Disambiguating information has different