Abstract: Xiaohuangshan ophiolites outcropps in active continental margin,a great fault zone during the Early Paleozoic Era in nort heastern edge of Talimud land mass.The ophiolite was mainly composed of serpent inite,peridotite,pyroxenite,gabbro,diabase and limest one,the features of major elements and REEof basic volcanic rocks were similar to the OIT,and the features of trace elements were similar to the IAT.It had the general characteristics of tectonic ophiolite mixtite.According to the out cropping scale and the rock-group,the forming tectonic environment showed that it was the out come of island arc spreading, and formed during late Cambrian Epoch-early Ordo vician Epoch.It was later superimposed and reconstructed during at least 4 age deformation-metamorphism,and moved to the earth's surface at late Devonian.