Abstract: Objective To observe the effect of magnesium isoglycyrrhizinate on proliferation of Molt4 cells. Methods Magnesium isoglycyrrhizinate was diluted to 8 groups at different concentrations（10g/L,1g/L,10^-1g/L,10^-2g/L,10^-3g/L,10^-4g/L,10^-5g/L,10^-6g/L）.The Molt4 cells were incubated with magnesium isoglycyrrhizinate solution at these concentrations,and cell growth status was chronologically observed under microscope.CCK-8 assay was employed to detect the ability of cells to proliferate and growth curve was plotted for calculating the inhibition ratio and 50% inhibiting concentration（IC₅₀）. Results Maganesium isoglycyrrhizinate inhibited the proliferation of Molt4 cells proliferation in a time-and dose-dependent manner.The proliferation of Molt4 cells was significantly inhibited on day 3 after treated with magnesium isoglycyrrhizinate at the concentration of 10^-3g/L（P＜0.05）.The inhibitory rate for 10g/L,1g/L,10^-1g/L,10^-2g/L and 10^-3g/L was 87.1%,64.6%,48.7%,47.5% and 31.7%,respectively.The IC₅₀ was about 0.013g/L. Conclusion Magnesium isoglycyrrhizinate can inhibit the proliferation of Molt4 cells,,thus providing an experimental basis for the treatment of hepatic lesion correlated with leukemia chemotherapy with magnesium isoglycyrrhizinate.