Abstract: We investigated the characteristics of breeding microhabitat of Saunders′ Gull ( Larus saundersi ) in the spring and summer of 1999, 2000 and 2001. Three types of breeding habitats of Saunders′ Gull were recorded: Spartina anglica community, Suaeda glauca community and Aeluropus littoralis community. We compared the nesting habitat availability with nesting habitat utilization in these three habitats. The results showed that Suaeda glauca habitat was positively selected by Saunders′ Gull, and Spartina anglica habitat and Aeluropus littoralis habitat were avoided. Indicated by the studies on microhabitat selection, the characteristics of breeding microhabitats where Saunders′ Gull prefer to nest included that plant height is more than 5 cm and less than 25 cm, vegetation coverage is 20% to 60%, biomass of zoobenthos is above 300g/m², distance to water source is 500m to 1000m, and distance to artificial disturbance is more than 500m. Beach exploitation and human activities along the coast of Yancheng were the major factors influencing breeding microhabitat selection of Saunders′ Gull. Some suggestions are put forward for protection and management of breeding habitat for Saunders′ Gull.