0.05).The results of electrocardiography and the laboratory ex-amination showed that neither ANWin cluding natural Calculus Bovis nor A NWincluding in -vitro cultured Calc ulus Bo-vis had obviously toxic and side effe cts in treating epidemic encephalitis B.Conclusion ANW including in -vitro cul-tured Calculus Bovis has an markedly effect in the treatment of epidemic e ncephalitis B.