The respiration and glycolysis of the spleen of mice was measured on the primary and transfered leukemia. This transfered leukemia was 292-314 transfers of Line OHOLL No. 1 of transmissible lymphatic leukemia of DBA mice which are derived from the spleen of induced lymphatic leukemia DBA mice by painting with methylcholanthrene. Whether the metabolic differences between the primary and transfered leukemia have relation with the virulence of leukemic cell or not, was discussed. For purpose of studies on relation between cell virulence and metabolic differences, the respiration and glycolysis of two ascites cells, Line OHOLL No. 1 and C(3)HF mouse transmissible lymphatic leukemia which are derived from the spleen and the lymph-nodes of C(3)HF spontaneous lymphatic leukemia, was measured. 1) There was no metabolic difference between the spleen in 292-314 trasfer of Line OHOLL No. 1 and the spleen of primary leukemia. Cell virulence that was proved by life span increased by transmission in long times, but cell metabolism did not alter. 2) Q(O(2)), Q(O(2))(M) and Q(N(2))(M) of Line OHOLL No. 1 ascites cell was higher than those of ascites cell of C(3)HF mouse transmissible lymphatic leukemia. There are the correlation between Q(O(2)), Q(O(2))(M) and Q(N(2))(M), and both ascites cell virulence. Q(O(2)): Q(O(2))(M): Q(N(2))(M) of two ascites cell was equal.