It was formerly believed that there were 3 populations of Larimichthys crocea distributed in the China Sea. Among these, individuals in the waters of Daiquyang, Zhejiang province and Guanjingyang were thought to belong to different populations. We reviewed the delineation of populations of L. crocea in the East China Sea and Yellow Sea based on a suite of methodologies, including geographical isolation, population dynamics, and ocean hydrology, so as to provide a rigorous basis for the division and to improve our ability to track declines in a given population. We used catch statistics of L. crocea from 1971 to 1982 from several major fishing companies. We identified two over-wintering grounds in the northern offshore and the southern near-shore regions of the East China Sea. The over-wintering resources in the Mindong-Wentai fishing grounds played a dominant role in the southern near-shore region of the East China Sea. The Guanjingyang L. crocea population overwintered in the waters of Mindong. Given this, the Guanjingyang L. crocea population was assigned to the East China Sea & Yellow Sea population. Two additional lines of evidence support this assignment. First, during a mark recapture study, a male large yellow croaker that was tagged at Daiquyang on May 20, 1958 was caught in Lianjiang (26°21′5″N, 119°50′E, 32 meters) on April 21, 1959. Thus, the populations in both Mindong and Daiquyang waters should be the same population with mutual inhabitation. Second, the East China Sea coastal current and the Taiwan Warm Current affect the coastal waters of Fujian and Zhejiang year round. Therefore oceanographic conditions are unlikely to cause population isolation.