Objective To insure the health of experiment mice, since 2009 our lab tool laboratory rodents from Beijing area to investigate the health status of laboratory rodents. We mainly use the pathologic method to investigate experiment mice. Methods The specimens we took from the experimental animals were mainly hearts, livers, spleens, lungs, kidneys, small intestines and large intestines. Specimens were immediately fixed by formalin. HE staining sections, PAS staining sections, oil red "O" staining frozen sections were observed under light microscope. Results According to the pathological examination there are different degree of pathological changes among the organs of laboratory rodents, such as hepatic and kidney. Conclusion Combined with the result of microbial detection, the laboratory rodents are not infectious with Pathogenic microorganism, such as bacteria, virus and parasite. And they have no harm to human beings, other animals and the surrounding environment. But small parts of laboratory rodents show certain extents pathological anomaly in clinically.