Objective: To investigate the effect of different mechanisms of liver-protection drugs in clinic and compare which one is best for the proliferation of irradiated HL-7702, laying the basis of liver-protection drugs choose in clinic on theory and practice. Methods: Human liver parenchyma cells HL-7702 were given single 6 MV X ray irradiation at a dose of 10Gy, the cells’ morphology were detected under an inverted microscope at 24h, 48h and 72h. Then, MTT was used to assess the survival rate of the cells to evaluate the effect of the X ray. The representive medicines which mechanism may relate to RILD were chosen and diluted into various concentrations with culture medium according to clinical and relative reports. Different concentrations of medicines were used to protect the cells damaged by the X ray. Comparing the effect with MTT and measure SOD, MDA for the best one. Further research on its protection of oxidative damage. T-test, F test and non- paramiter test were used for statistical analysis. Results: 2.5 mg/ml and 1 mg/ml of magnesium isoglycyrrhizinate both have an effect on the proliferation of liver cells, especially the concentration of 1 mg/ml. The injection of polyene phosphatidyl choline show trivial effect at the concentrations of 250 μmol/L and reduced glutathione(GSH) did not demonstrate relative functions. Further research on the magnesium isoglycyrrhizinate, found its protection at 48h to oxidative damage (P < 0.05), but the effect is weak at 24h and 48h. Conclusions In three kinds of representing medicines, magnesium isoglycyrrhizinate has preferable effects on liver parenchyma cells and show a bright future in the treatment of RILD.