Abstract: For establishment of a better metastatic model of tumor cells we have established a Spontaneous metastatic model of maine reticular cell sarcoma L_Ⅱ in inbred 615-strain mice. Tumor cells were inocubated into intramuscle of right hind tight and subcutaneous of right costal region as to observe metastatic characteristics in mice. The experimental animals were killed at moribound condition. The lung and lymph nodes were examined by naked eye and histology. It was found that all 24 animals of intramuscul inoculation had spontaneous lymphatic and lung metastasis simutaneously. In 23 animals of subcutaneous inoculation, 95.7% spontaneous lytnpbatic metastasis, 60.9% spontaneous lung metastasis and 56.5% simutaneous lymphatic and lung metastases were occured. The results of this experiment showed that this model possesses the nature of both directional metastasis to lymphnodes and lung.