o study and comparison the characteristics of high and low met-astatic cancer cells, two quamous carcinoma cell strains derived fromthe mouse forestornach carcinoina cell line (MFC) being possessedspontaneous hemotogenous metastasis by clonal technique and transplan-tation experinient have been established. Some comparative studies bet-ween the cells of MFC-C34 and MFC-C64 on the doubling time. mitoticindex, growth speed of tumor transplantation of the cloned cells inmice,the incidence of lung metastasis, the electrophoretic mobility ofliving cells were carried out. Shorter doubling time, higher averagemitotic index,faster growth speed and bigger volume for the tumor formedby homeotransplantation, higher incidence of lung metastasis, fasterelectrophoretic mobility were seen in the AIFC-C34, with significantlystatistical difference as compared with MFC-C64, a low metastaic capa-city cell strain.MFC-C34 and MFC-C64 cell strains will be very useful materials forthe study of the characteristics of metastatic cancer cells and experi-mental treatment of the metastasis.