In this study,sulfur content of the leaves and chlorophyll fluorescence of 9 garden plant species from Shenzhen were measured in November 2005 to evaluate effect of atmospheric SO₂ in order to select bio-indicators for atmospheric SO₂ monitoring. These plant species include Excoccaria cochinchinensis,Sanchezia nobilis,Codiaeum variegatum,Saruma henryi,aryota mitis,Ficus microcarpa var.pusillifolia,Ficus altissima,Pittosporum tobira and Duranta repens cv.\'Dwarf Yellow\'. Leaves from the 9 plant species were treated with distilled water and NaHSO₃,their sulfur contents and chlorophyll fluorescence were measured under light or dark conditions at temperature of 25℃. In the natural condition,the sulfur content in leaves of Sanchezia nobilis was the highest,and that for Codiaeum variegatum was the lowest. The sulfur contents of leaves treated with distilled water from the 9 species showed small change. When treated with NaHSO₃,the sulfur contents in sevenof the 9species increased,especially in the leaves of C.variegatum. The same 9 species were collected from two gardens where the atmospheric SO₂ concentration is different: Small Nan Hills with high air SO₂ and World Exhibition Park with low air SO₂. Except for P.tobira,the other 8 species had higher sulfur contents and lower F_v/F_m in Small Nan Hills than in the World exhibition Park. This result demonstrates that F_v/F_m of the 9 plant species is a suitable parameter to indicate pollution from atmospheric SO₂.