In previous study, two eukaryotic expression plasmids pSG.SS.YL-F(beta.ECD) and pSG.SS.C3d3.YL-F(beta.ECD) were successfully constructed and transfected in HEK293 cells. Now, we want to evaluate the immunocontraceptive effect of these two DNA vaccines that target the extracellular domain (Fbeta.(ECD)) of sperm antigen fertilin beta subunit in Kunming male mice.