Objective : The objective of this study was to investigate the experimental efficacy of anti-tumor activity of the complexed herbal formula, Onbaekwon (OBW), which was derived from the literature of Traditional Korean Medicine, Dongeuibogam. Methods : Nine Cancer cell lines, LoVo, MCF-7, HepG2, AGS, A549, NCI-H69, HL-60, Sarcoma 180, LL/2, were prepared and the cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2yl)-2,5-dephenyl tetrazolium bromide (MTT) assay. Four of them, NCI-H69, HL-60, Sarcoma 180, and LL/2, showed strong cytotoxic activities and they were additionally undergone flow cytometry to find out their effects on apoptosis. ICR male mice were implanted with Sarcoma 180 intraperitoneally and divided into 8 species for each group. Control group was treated with normal saline, positive control group was treated with cyclophosphamide 8mg/kg, and experimental group was treated with OBW 1 g/kg. Results : Among 9 cancer cell lines, NCI-H69, HL-60, Sarcoma 180, and LL/2, expressed less than 0.10 mg/ml of $IC_{50}$ under 0.1~1mg/ml of OBW. NCI-H69, HL-60, Sarcoma 180, and LL/2, showed dose-dependent efficacy of apoptosis. When Sarcoma 180 cancer cell was implanted in ICR male mice and treated with the OBW, they prolonged the median overall survival for 0.8 days, from 17.5 to 18.3. Conclusion : OBW showed strong cytotoxicity to some cancer cells, which are NCI-H69, HL-60, Sarcoma 180, and LL/2, and its apoptotic activity was dose-dependent. OBW prolonged the median survival of mice implanted with Sarcoma 180. Further researches would be expected to support the efficacy of OBW.