Abstract: Objective The etiologic fraction and interaction of risk factors of Tourette syndrome(TS)were explored on the basis of the condional logistic regression analysis.Methods One hundred cases with TS and 100 controls were conducted by 1:1 matched case-control study in Wenzhou.Results Multiple conditional logistic regression analysis showed that family history of TS,nocuous mental sitmulation during early pregnancy and highly fever(T>39℃)were the independent risk factors of TS.Etiologic fractions of the independent risk factors were 0.161,0.135,0.126 respectively.The interactions between family history of TS and risk factors which included highly fever(T>39℃),nocuous mental stimulation during early pregnancy were analysed.The result revealed that EF(AxB)(etiologic fraction attributable to interaction)were 0.629,0.069 respectively.The interaction index were 0.675,0.078 respectively.Conclusion These findings indicated family history of TS,particularly those having higly fever(T >39℃),increases the risk of TS.