Abstract：A low-grade metamorphic series composed of marine sandy, muddy and siliceous sediment is widespread in Changting and Shanghang, southwestern Fujian. According to the regional geological survey of the 1：250000 Ruijin Sheet, the “Dingwuling conglomerate” is determined to be of Late Devonian age and thus separated from the low-grade metamorphic series. In this paper, the low-grade metamorphic series that conformably underlies the Lower-Mid Cambrian Lintian Formation is divided into the Jiangshekeng Formation，Laikeng Formation，Nanyan Formation and Huanglian Formation.