Two-dimensional (2D) gel electrophoresis followed by mass spectrometry was utilized to compare the protein expression between male worms of single-sex infection and male worms of bisexual infection in Schistosoma japonicum. To observe the in vitro expression and subcellular localization of recombinant eukaryotic expression plasmid pEGFP-C1/ SJCHGC in COS-7 cells and analyze the antigenicity of the products expressed. 9 pairing-related proteins were identified and further validated by semi-quantitative RT-PCR analysis. Most of the candidate proteins have been evident to be somehow associated with various aspects of S. japonicum such as cell growth, development, motility, reproduction, nutrition and signal transmission. The SJCHGC gene was expressed in the transfected COS-7 cells. The expression and subcellular localization of the fusion protein were analyzed by fluorescence microscopy. The proteins expressed show the antigenicity of Schistosoma japonicum. These results provide the basis for elucidating the Schistosome mechanism of development and reproduction, and may permit the identification of protein candidates for the development of novel vaccine or new targets for drug development against schistosomiasis.