Objective To explore the therapeutic effects an d the appropriate treating time of the artificial liver support system through obs ervation and analysis of the changes of the liver function indexes before and af ter the treatment of the artificial liver support system. Methods The changes of BIL-T, BIL-D, ALT, AST, ALP, TBA, ALB, GLB, A/G of the liver fu nction indexes in a total of 38 cases with serious hepatitis treated by artifici al liver support system were observed. Besides, the dynamic changes of the BIL- T, ALT of one case of middle stage and late stage serious type hepatitis respect ively before and after the artificial liver treatment several times were observe d. Results The BIL-T, BIL-D, ALT, AST, ALP of the liver func tion indexes after the artificial liver support system treatment showed remarkab le decline, significant differences existed before and after the treatment (P