【摘要】The paper presents the application of Threshold Auto-Rcgrcssivc(TAR)mod-el in dealing with the nonlincariYy in economy. With SETAR model,forecasting of 31 Chinas macrocconomic series is performed and the accuracy of different preprco-cessing methods arc compared.With TARSC model·Chinas Adjacent National In-come Index and Accumulation rate arc used Yo analyze economic fluctuation,cmpir-ical in Ycrpretation of the fluctuation and leading and lagging arc also presented.The results of the application arc satisfactory.