Small yellow croaker (Larimichthys polyactis Bleeker), one of the most important demersal trawling fish in China, is widely distributed in the Bohai Sea, the Yellow Sea and the East China Sea. This fishery has undergone a prosperous-decline-recovery chronological development in the past 50 years. During the recent recovery period, the annual landing of this fish has increased from 20000 t in the late 1980s to the current 300000 t. Compared to its population biology 50 years ago, reduction of individual size, advance of maturation and accelerated growth are frequently observed in the current wild small yellow croaker population, suggesting its vulnerability to fishing pressure and environmental changes. Our previous studies revealed that the mid-summer moratorium regulations implemented in the spawning grounds from 1995, and the changes of reproductive strategy of individuals are potential driving forces for the recent fishery recovery. Understanding the changes of the spawning grounds is also critical for exploring the mechanism governing the fishery recovery, but there is little information available on this topic at present. Based on the data collected from demersal trawling surveys conducted in the southern Yellow Sea and the East China Sea in April of 2003, 2004, 2005 and 2007, the spatial distribution and environmental characteristics of spawning grounds of the small yellow croaker are investigated. The results indicate that the spawning grounds have obviously expanded from the near-shore to offshore waters in the recent years. Two spawning grounds are discriminated in the current investigation. One is located in the Yellow Sea ranging within 33°00′-34°00′N, 122°30′-124°00′E. This area was environmentally characterized by an optimal water temperature of 9.65-12.17℃, a salinity of 32.25-34.54 and a water depth of 29.74-76.49 m in April. The other one includes two parts in the East China Sea: 30°30′-31°00′N, 124°00′-125°00′E and 30°30′-32°30′N, 125°00′-126°00′E with an optimal water environment of 10.13-16.64℃, 32.50-34.37 and 4023-85.61 m, respectively. Spatial extension of the spawning grounds may be an ecological adaptation strategy of the small yellow croaker to overfishing and environmental changes in nature.