Abstract: The whole-rock Sm-Nd isochron age of the amphibolite occurred in the garnet-mica schist from Lean Xiangshan and derived from tholeiitic volcanic rock is 1113±49 Ma. In combination with the isotopic dating results of amphibolites in Yiyang Meishuwan and Yijiang Maquan ((1159±69 Ma，Sm-Nd; 1190±19Ma, U-Pb respEctively ), it is confirmed that the original rocks of central Jiangxi metamorphic belt belong to Mesoproterozoic strata. By means of fuzzy cluster analysis on trace element geochemical ratio between Chencai Group in west Zhejiang,Sinian System and metamorphic rock in Jiangxi, in combination with the Pb-Nd isotope geochemical features of amphibolites,it is identified that the central Jiangxi metamorphic belt is closely correspond to the Chencai Group and belongs to Cathaysian block. On the basis of a detailed comparative study on the deep geophysical features of gravitation and magnetic fields and the distribution of stratra and magmatic rocks on both sides of the Congren-Linchuan-Dongxiang Cretaceous red-bed fault basin, it is inferred that the northwest boundary of Cathaysian block may be limited by the Suichuan deep fault.