Annona muricata Linn. or soursop containts acetogenin which can induce apoptotic in in vitro assay and has cytotoxic effect. The study has been done to examine the soursop leaves extract's potency in in vivo assay to suppress tumor development by 7,12- dimethylbenz[a]anthracene (DMBA) induced. The induction process has been done twice a week for five weeks to white rat, Sprague Dawley's strain. The soursop leaves extract were given into three doses, 200, 400, and 800 mg/kgBW, for seventeen days after two weeks induction with DMBA. The analysis of histopatology and the study of proliferation activity of hepatic cell with AgNOR showed significant reduction of proliferation activity. In conclusion, the soursop leaves extract has potency as antiproliferative agent to hepatic tumor in in vivo study.