T he sulfur dioxide pollution deg ree was monito red by leaf chlorophy ll content analy sis of 4 woody plant species in 5 districts of Sheny ang City. Average contents of chlo rophyll were 3 .56, 4 .73, 4 .88, 5 .33,5 .39 mg/ dm2 for T iexi, Huanggu, Heping , Shenhe and Dado ng districts respectively, which indicated that SO  pollution in Tiexi district is severe and Dadong district is the lightest .