Abstract:In order to study the origin of germ stem cells, the biological characteristics and the mechanism of cell differentiation . The CR4 and CR1 Fragments of Oct4 promoter were inserted into EGFP eukaryotic report vector and to reconstruct a mouse germ cell-specific enhance green fluorescent protein (EGFP) report vector. The recombinant plasmid was subsequently transfected into a variety of cells using Liposome 2000. Expression of the EGFP were detected under Fluorescent microscopy . the germ cell-specific gene expression was semi-quantitative detected in transfected cells by RT-PCR. The results showed that the green fluorescent protein expressed in testicular and P19 cells. In mouse embryonic stem cells, mouse embryonic fibroblasts (MEF) and C2C12 cells GFP did not express. RT-PCR showed that P19 and testicular cells express Oct4 and other germ cell-specific markers. The results suggested that the recombinant vector specificity expressed in germ cells and it will be an available tracer for the study of germ stem cell by fluorescent imaging,also it could be used to show the pluripotential state of germ stem cells.