The biological characteristics, geographic distribution, population structure and ecological speciality of Dosinia gibba in the north Yellow Sea were investigated. The results indicate that D.gibba in this sea area are cetrally scatter-ed in the subtidal zone (water depths of 0-2m) in 39°25'～39°39'N,122°35'～123°04'E. They perched in the sandy silt bottom of the sea. They are the creatures of near land ecotype. Most of them are two year of age. The relationship between body weight and shell length is exponential. The regression is egpressed as W=0.003936L^2.812. The communities constitution and the ecological distribution of the mores in D.gibba settlement were analysed as well. And the sperciality of water che-mical and nutrient environment were elucidated. The ecological niche and system of D. gibba were discussed. D.gibba settled in the fauna of bivalve molluscs of this sea waters. The maximum biomass is 0.44g /m² and abundance is 0. 06 ind/m²，Here they have not become the dominance population yet. It is 28-30℃ that the yearly changes of vvater temperature in the present waters. The salinity is changed between 20‰and 32‰.