The drug-containing sera from the rats with oral administration of GuizhiTang were inactivated.The effects of the sera with or without inactivation were investigated on HSV-1-induced CPE action.The result showed that the following measures should be taken when the sera of animals post-administration of Chinese medicine were used in an in vitro study:(1)A serum control should be set to establish the effect of serum itself on the study system.(2)It could be better to use inactivated drug-containing sera because the antibody and complement of the sera could be eliminated after inactivation.(3)More doses considering the clinical equivalent effect-dose as the middle one should be designed according to the characteristics of Chinese prescription to correctly evaluate the real effect of drug-containing sera.