Abstract: Based on the study of petrology,mineralogy,microelements,palaeontology and geological occurrence characteristics,the authors hold that the thick-beded metamorphic conglomerate in Sinian strata in Laoshouxia,Luoding area of westren Guangdong province,is a sedmental basal conglomerate with simple component suffered structural deformation.Its bottom surface is corresponding to one of Nantou Formation in South China,and is the structural surface of Chengjiand movement between early to late Sinian period in Guangdong region.