The sedimentation of Upper Sinian carbonate rocks along the northern margin of the middle Yangtze platform occurred in two facies areas, namely shallow-water platform and deep_water platformal basin ,which include seven facies zones. There exists close relationship of Sr content and Sr/Ca×1000 ratio to the sedimentary environment, i.e., the values increase obivously from the shallow-sheal facies to the deep-water platformal basin facies. This is attributed to the infuence of the difference in carbonate mineralogy in different sedimentary environments on the Sr distribution and also to the diagenetic environment which depends upon the sedimentary environment. The content of the trace element Sr and the Sr/Ca×1000 ratio can therefore be used to judge sedimentary facies.