A suite of amphibolites associated with marble from Chencai Group is exposed at Xiahetu Village in Zhuji County of Zhejiang Province. Detailed geological and geochemical studies were carried out on the Xiahetu amphibolites. The SiO₂ content of the amphibolites ranges from 43.22% to 46.56%, MgO content ranges from 3.23% to 7.87% and TiO₂ content ranges from 1.90% to 2.98%. All these geochemical features are similar to the average value of oceanic island basalt (OIB). Moreover, the major elements characteristics of the amphibolite suggest that it belongs to the alkali basalt series. The total REE values of the amphibolite range from 114.47×10^-6 to 192.39×10^-6, and (La/Yb)_N ratios range from 5.93 to 12.13. The chondrite-normalized REE patterns show right-inclined shape, which suggests the enrichment of LREE. The primitive mantle normalized trace element spider diagram shows obvious uplift, which is also similar to the feature of oceanic island basalt. Some tectonic discrimination diagrams suggest that Xiahetu amphibolites were formed in an oceanic island tectonic environment. Petrogenetic research shows that the protolith of the amphibolite had experienced a little crust contamination during the magmatic events. So the geochemical features of the amphibolite can be used to infer its original mantle features. It is held that the protolith of the Xiahetu amphibolits possibly formed in a marine volcanic geological setting near the subduction zone and sourced from the seamount fragments accretion during the subduction of the oceanic crust. Thus rocks in Chencai Group are probably a suite of subduction-accretionary complexes. U-Pb dating results of zircons in the amphibolite yield a mean age of 420.6±1.8 Ma which represents the metamorphic time of its protolith. In conjunction with other field evidence, the authors consider that the amalgamation between the Yangtze and Cathaysia Blocks was completed in Caledonian.