The researches about neurocognitive mechanisms of sentence processing in second language are at their stage of verification and exploration, primarily concentrating on the comparisons on reaction patterns between syntactic and semantic anomalies in native and second language. As for semantic processing of second language, the results are contradicted, which might be related to age of second language acquisition. For syntactic processing, second language learners showed their dependence on age of second language learning. Meanwhile, syntactic processing of second language depended on the similarities and discrepancies between native and second language, which might reveal the syntactic accessibility between them. The future studies should focus on the effects of systematic changes of semantic and syntactic accessibility on second language processing as well as the comparison on neurocognitive mechanisms between native speakers’ native and second language processing.