Objective:To study the effects of compatibility circumstances on guizhi's effect in dispelling cold and relieving exterior in complex prescriptions. Methods:202 formulae that effected on Sanhanjiebiao were collected from 1425 formulae with guizhi,and the frequency of herbs combining with guizhi in 202 formulae was ranked from high to low. Results:According to the compatibility frequency from high to low,herbs are:Radix Ledebouriellae(60.89%) ,Herba Ephedrae(36.63%) ,Notopterygium Incisum Ting ex H.T.Chang(27.23%) ,Radix Angelicae Dahuricae(14.85%) ,Rhizoma Zingiberis Recens(11.39%) ,Herba Schizonepetae(5.94%) ,Radix Ledebouriellae and Herba Schizonepetae(4.46%) successively. Conclusion:It showed that guizhi should combine with corresponding herbs to form compatibility circumstances to exert the effect of Sanhanjiebiao in formula,and the function exertion will be effective.