Abstract Bilingual individuals need to switch one language to the other to understand different language information in daily life, such as reading and listening,which is called bilingual comprehensive switching.Previous studies mainly investigate whether the non-target language was activated when bilinguals intended to process the target language,different researchers have inconsistent results with diverse methods. Therefore, this study was used to further investigate the activation of non-target language.Non-target language can be divided?into phonological level and semantic level,we explore the activation of these two levels with an immediate cross-language priming paradigm.In the end,the event-related brain potential (ERP) technique will be used to record the data. The experiment 1 takes the language switching direction,the area of the brain,the pair of words type as the independent variables.The P200 peak latency and the peak value of P200 are the dependent variables. The experiment 2 takes the language switching direction,the area of the brain,the pair of words type as the independent variables.The N400 peak latency and the peak value of N400 are the dependent variables. Twenty Chinese-Uyghur bilinguals participated in experiment 1,sixteen Chinese-Uyghur bilinguals participated in experiment 2,all of participants were Chinese natives,and Uigur was their unskilled second language.The phonological decision task was conducted in the Experiment 1.Target words (one language) were appeared immediately after prime words (the other language) which were phonologically related to the translative equivalents of target words (Experiment 1).Participants were followed the instruction carried out the phonological decision task.The conceptual decision task was conducted in the Experiment 2.Target words (one language) were semantically related to the translative equivalents of target words (Experiment 1). Participants were followed the instruction carried out the conceptual decision task. The behavior data and ERP data both were recorded and analyzed. The investigation results show that, in experiment 1,phonologically related target words?group?and?phonologically unrelated target?words group?are?significantly different，the switching direction L1–L2 and direction L2-L1 also are significantly different.We could conclude that phonological level of non-target language was automatically activated.There were significantly RTs and N400 difference between semantically related target words and semantically unrelated target words no matter the switching direction was L1–L2 or L2–L1. So there was strong evidence of cross-language semantic priming,and we found differences refer to spatial distribution of N400. Besides, the results provided evidence for the phonological priming asymmetry,with larger priming from L1 to L2 than the reverse,and different kinds of temporal and spatial P200 priming effect (the ERP difference between two types of target words,between two switching direction).For L1-L2 switching P200 priming effect was weaker and The P200 latency was earlier，The most significant activated region located in the right side of the frontal lobes.For L2-L1 switching P200 priming effect's most significant activated region located in the middle side of the frontal lobes. In conclusion,according to the results the phonological level of non-target language will be activated during the phonological decision task,and the switching cost was asymmetric.And strong evidence was found for the semantic level activation of non-target language during the conceptual decision task.