This paper investigated the inhibition of homoharringtonine which effected on human hepatoma HepG2 cells by MTT,in vitro.11 treatment groups of homoharringtonine(24,48,72 h) was designed to explore inhibition.Compared with control group,the inhibition rate was increased with the increase of homoharringtonine.The results indicated that homoharringtonine could inhibit the proliferation of HepG2 in vitro.