Abstract:A total of 2820 Saunders′s Gulls Larus saundersi, including 31 adults and 2789 fledglings, were marked with individually coded flags at Shuangtaihekou National Nature Reserve in June each year from 1996 to 2008. Based on 2729 resighting records in 23 wintering sites, two migration routes of Saunders′s Gulls breeding at Shuangtaihekou were suggested: migrate eastwards to winter in the southwestern coast of South Korea and the western coast of Japan; and migrate southwards to winter along the coast from Tianjin to eastern seas of China, including western coast of Taiwan. The overall annual chick survival rate of (7.77±4.00)% were estimated from 1996-2007, ranging from 1.67%-14.89%. During the study period, relative survival rates in 1997, 2001, 2004, 2006 and 2007 were lower than the average, with the lowest of 1.67% in 2006. Using the Cormack-Jolly-Seber (CSJ) model of the software MARK, average annual survival rates of 0613±0.058 and 0.746±0.042 and average annual resighting rates of 0.897±0.04 and 0.799±0.053 were estimated, respectively, for sub-adults and adults. Higher resighting rate of sub-adults over adults possibly was because the sub-adults intended to form large flocks during the wintering. We recommend the resighting effort be made as much as possible in the future, so to understand the winter movement among the gulls at different ages.