Based on the observational data in August 2006 obtained by buoys, automatic weat her stations and radio sounding in Qingdao Region, a typical landsea breeze ca se is studied in detail, and verified by WRF modeling results. The results indic ate that both sea breeze circulation and land breeze circulation in the vertical direction are closed, and the thickness of seabreeze circulation is much thic ker than land breeze circulation. Seabreeze appears and disappears firstly in the lower level, which is strongest in the afternoon. The wind force decreases w ith height. When the landsea temperature difference between Qingdao Station an d buoy station reaches to 4℃，sea breeze occurs，which can extend to inland about more than 40km. The WRF model successfully captures the sea breeze circulation, and reveals the interaction b etween sea breezes on both sides of the peninsula, which results in the converge nce and ascending in the middle part of the peninsula.