Abstract: An electron probe microanalyzer was used to analyze the element Sr and Ca accumulation patterns in otoliths of two individuals of Coilia nasus from the Xingzi area in the Poyang Lake, China. Results of both the line transect and mapping analysis confirmed objectively, for the first time, the coexistence of resident and anadromous forms of Coilia nasus in the Poyang Lake. This fact will provide important information not only to more effectively evaluate and protect the resources of Coilia nasus, but also to rationally plan and guide future ecological economic development in the Poyang Lake.