Abstract: Objective Establishment of B7-DC transgenic mouse model. Method B7-DC cDNA was cloned by RT-PCR from mouse thymus, then it was inserted into PEF6/V5-His vector and get PEF6-B7-DC/V5-His which contain a fuse protein B7-DC-V5-His. The PEF6-B7-DC/V5-His gene was microinjected to the pro nuclear of FVB mouse embryos, then transfer the embryos to the foster mother and get new individuals. Positive founders was confirmed by PCR and Southern. Result Eighty three injected embryos were transferred and 39 offspring mice were obtained, three of them are positive and can be successfully inherited to F2. Conclusion The B7-DC transgenic mice model was established.