Abstract: This paper reports the effects of long-term exposure of low concentration SO₂ on the growthand yield of soybean （Glycine max）.The potted plants are exposed in the chamber 7 hoursper day for 40 days.SO₂ concentrations are 0,100,150,200 and 25O ppb.The results showthat SO₂ reduces the content of pigments,leaf area and the dry weights of leaf,shoot androot.The effects of SO₂ on the growth and yield of soybean are intensifing with increasing exposure doses.The dry weight and yield of soybean are also reduced obviously by SO₂even under the concentration with no visible injury to leaves.

Key words: eco-environment, vulnerability, remote sensing, GIS, Pearl River Delta