Objective : This Study was to investigate effects of Takliikgi-tang on the anti-cancer and proliferation of immunocytes, nitric oxide (NO) production of peritoneal macrophages. Methods : We used Takliikgi-tang extract (TLT) with freeze-dried, 8weeks-old male mice and cancer cell lines (L1210, Sarcoma-180) for this Study. The cytotoxicity and proliferation of cells were tested using a colorimetric tetrazoliun assay (MTT assay). Results : 1. TLT was significantly showed cytotoxicity on the L1210, 5-180 cell lines. 2. TLT was significantly increased proliferation of thymocytes in vitro. 3. TLT was significantly increased proliferation of thymocytes and splenocytes in normal mice. 4. TLT was significantly increased NO production from peritoneal macrophages in normal mice. 5. TLT was significantly decreased proliferation of L1210 cells in L1210 cells transplanted mice. 6. TLT was significantly increased proliferation of thymocytes and splenocytes by all-dosage in L1210 cells transplanted mice. 7. TLT was significantly increased NO production from peritoneal macrophages in L1210 cells transplanted mice. Conclusions : The present author thought that TLT had action of anti-cancer by becoming immunocytes activity (NO production, proliferation of thymocytes).