Abstract: In this article,A type n conductance of ZnO thin film was deposited on the p-Si filim by magnetron sputtering Al doped ZnO ceramic target,and the ZnO/n-Si heterojunction was preparated.The photoelectric properties,charge carrier transport properties and conductive mechanism were studied by testing the I-V,C-V characteristics with illumination and without illumination.The results shows that there exists a good rectifying properties and photoelectric response for ZnO/n-Si heterojunctions,and can be widely used in photoelectric detection and fields of solar cells.As the conduction band and valence band offset in the ZnO/n-Si heterojunction is too big,the current transport mechanism is dominated by the space-charge limited current（SCLC） conduction at the forward voltage exceeds 0.8 V.The results suggest the existence of a large number of interface state in ZnO/n-Si heterojunction,and the interface states can be reduced and the photoelectric properties can be further improved.