Objective To study effect of Shikonin on human cervical cancer Hela cell growth suppression in vitro and its mechanism. Methods MTT assay was used to examine the growth inhibition of Shikonin in Hela cells.And then, the measurement of both ROS Levels and Mitochondrial Membrane Potential (ΔΨm ) were performed to clarify the mechanism of antitumor in Hela cells by Shikonin.Results Shikonin significantly inhibited the growth of Hela cells in a concentration-dependent manner.Shikonin increased generation of en-dogenous reactive oxygen species ( ROS) and decreased mitochondrial membrane potential.Furthermore, anti-oxidants N-acetylcysteine ( NAC) could significantly reduce the antitumor activity of SK in Hela cells.Conclusion These results suggest that mitochondrial aerobic respiration shift and endogenous ROS augmentation contribute to the action of Shikonin against Hela cells.