This paper makes use of time series trend and elastic model for empirical research on zero-tariff trade effect of litchi and longan in China and Thailand.Results show that the effect of trade creation of fresh litchi is greater than the effect of trade diversion and the effect of trade diversion of fresh longan and dried longan is greater than the effect of trade creation in most of years.In 2012 the effect of trade creation and trade diversion of fresh longan is maximum; the effect of trade creation of fresh litchi and dried longan is greater than the effect of trade diversion; the effect of trade diversion of fresh longan and dried longan accounted for the proportion of logan importing from other countries is greater than the fresh litchi.Then put forword : to enhance export competitiveness of litchi and longan industry and maintain the sustainable development,we need to increase financial support to the development of characteristic agriculture, adjust the variety and the maturity structure,make and improve the system of insurance policy of litchi and longan.