Sulfur dioxide (SO₂) is a major air pollutant and has a significant impact on the environment. Because of its widespread presence in air-pollution gases, SO₂ is one of the most important air pollutants in urban areas. Turf grasses are essential landscape plant species among the current urban greening, and understanding the physiological mechanism of turf grass resistance to SO₂ can help us choose suitable turf grass species for various types of lawn. In this study, three warm-season turf grasses-Zoysia (Zoysia japonica), Bahia (Paspalum notatum) and Bermuda (Cynodon dactylon)-growing under greenhouse conditions were selected and screened for tolerance to acute SO₂ injury. Five treatments including CK (0 mg/m³), S1 (4.29mg/m³), S2 (6.44mg/m³), S3 (8.58mg/m³) and S4 (10.73mg/m³) were used in this study, and release of SO₂ was achieved using the artificial simulated fumigation method. The plants screened for SO₂ injury were growing in a pair of sealed glass chambers in the greenhouse. Differential response to SO₂ injury among these three species was manifested by soluble sugar and protein content, and by the activities of peroxidase (POD), catalase (CAT) and the superoxide dismutase (SOD). Our results showed that the leaf content of soluble sugar, proline and malonaldehyde rose gradually as SO₂ concentration in the three grass species increased, each reaching its maximum at the level of 10.73mg/m³ SO₂. The relative increase of these three substances in Bahia was the largest among the three turf grass species, which suggested that Bahia was more susceptible than Zoysia and Bermuda to SO₂ injury. The accumulation of soluble protein in Zoysia showed a decline at 4.29mg/m³ SO₂ compared with the control, and reached its highest level at 10.73mg/m³ SO₂, whereas Bahia had the highest levels at 4.29mg/m³ SO₂. However, the accumulation of soluble protein in Bermuda decreased in all four SO₂ treatments compared with the control. These results implied that Zoysia is much more tolerant of SO₂ injury at higher concentrations than are Bahia and Bermuda. The activities of POD, SOD and CAT in Zoysia gradually increased with increments in SO₂ concentration compared with those in the control and reached the greatest level at the highest SO₂ treatment, achieving the highest levels of SO₂ at 10.73mg/m³. The activities of these three enzymes in Bermuda showed a similar trend to those in Zoysia, except that the relative increase was smaller. The activities of SOD and CAT in Bahia were higher at all four concentrations of SO₂ compared with those in the control, and the activities of SOD and CAT reached their highest levels at 6.44mg/m³ and 4.29mg/m³ SO₂, respectively. However, the activities of POD showed a reverse trend in Bahia compared with those in Zoysia and Bermuda; they gradually decreased, starting from the control through the four SO₂ treatments in ascending order. These results indicated that Zoysia and Bermuda had the stronger protective enzyme system under abiotic stress than Bahia. Combining all the results, we concluded that the resistance of the three turf grasses to SO₂ could be ordered in sequence from strong to weak as Zoysia > Bermuda > Bahia. This conclusion can guide us in respect of the large-scale use of Zoysia in heavily SO₂-polluted areas in tropical and subtropical regions.