Abstract: Through the field sampling and geochemical studies on Tongcun rock mass of Kaihua in Western Zhejiang，it is determined that Tongcun rock mass belongs to the granite porphyry of aluminous high-K calc-alkali series.Through the stable REE and trace elements，the types of rock mass and other features are determined.REE's distribution patterns are consistent with that of the same granite porphyry (I-type).The distribution of trace elements has a characteristics of large ion lithophile element enrichment，showing significant Ta，Nb，P，Ti negative anomalies，which are similar to the rocks under the environment of “island arc”.Compared with the bedrocks of porphyry deposit，it has not a good ore-prospecting potential.

Key words: Geochemistry, I-type granites, Tongcun granite porphyry