Abstract: Objective To supply some basic data for extension and application of BNX mice through observation on generally biological properties and peculiarity of tumor growth and metastasis after tumor implantation. Methods By the method of periodically measuring the weight、analyzing breeding character, graphing growth curve、examining hematological and blood biochemical parameters,we explored biological characteristics of BNX mice. At the same time，we also established tumor animal models of human gastric tumor （MKN-45） and human melanoma （SCI-375） in BNX mice through orthotopic and subcutaneous tumor implantation. Results It showed that there was a statistically significant difference of body weight between male and female BNX mice within 4?30 weeks （P＜0.05）. The number of WBC in peripheral blood haematology of BNX mice was only equal to twenty-five percent of that of normal mice,while no statistically significant differences in biochemical parameters was observed between BNX mice and normal mice. The metastatic rates of orthotopic implant models of human gastric tumor （MKN-45） and subcutaneous implant models of human melanoma （SCI-375） in BNX mice were much higher than in nude mice and SCID mice.Conclusions These results suggest that BNX mice are more suitable for the study of establishment of tumor metastatic models compared with nude mice and SCID mice.

Key words: BNX mice, Biological characteristic, Tumor model