Objective: ascertain the effective part of anti-tumor activity in Viscum coloratum (Kom.)Nakai f. Rubroaurantiacum Kitag(VCR). Method :We made sarcoma S180 mice as the animal model

the inhibition rate of tumor was used as investigation index. We carried out the screen assay of the anti-tumor for different solvent extraction part of the VCR extracts by 75% alcohol

including petroleum extraction part

chloroform extraction part

acetate extraction part

n-butanol extraction part and the rest. We randomly divided mice with inoculated tumor into 7 groups according to tumor size. The positive control group of mice were given ip cyclophosphamide of 100 mg ·kg-1

the other experimental group at the same time were given ig of 14.2 g ·kg-1 ·d-1 and the blank control group were given the same volume of the blank solvent

continuously administrated for 8 days. Result: The results showed that the extraction of VCR could obviously prevent the growing of the tumor in mice. The inhibition rate of tumor for the chloroform extraction part was 48.8%;the rate of the n-butanol extraction part was 44.1%. Conclusion: The chloroform extraction part and the n-butanol extraction part are the effective part of anti-tumor from VCR.