Objective To monitor the genetic quality of the new wild derived inbred strain of mice trapped originally in China. Methods According to national standard, GB/T14927 1-2001, GB/T14927 2-2001 and the procedure from International Laboratory Animal Commission, 25 biochemical markers for genetic monitoring of TW (Tianjin Wild) inbred strain were performed, and skin grafting test was also carried out. Results Measurement of 25 biochemical markers gene loci was performed by electrophoresis and the results revealed that all observed gene loci were homogenous without any polymorphism and mutation. Of the 25 loci observed, 8 were found to show the rare subtypes. The skin grafting test showed that no dropping graft was found during 100 days after transplantion, implying the TW was of isohistogenicity. Conclusion\ The TW inbred strain mouse is high homogenous in the genetic characteristics and it is possible for the TW inbred strain to be a standard model of genetic monitoring of biochemical markers.