In order to explore the mechanism of shady perennial plants to sulfur dioxide (SO₂) resistance and phytoremediation of air pollution, we selected and screened three shady plant species including Ophiopogon japonicus, Saxifraga stolonifera，and Hosta ventricosa growing under the greenhouse condition for tolerance to SO₂ injury and purification of SO₂ in this study. SO₂ treatment was achieved through an artificial simulated fumigation method，and SO₂ was set as the following four concentrations: 5.71, 11.43, 17.43 and 22.86 mg·m^-3. The differential responses to SO₂ stress among the three plant species were manifested through the phenotypic injuries and the various physiological indexes, and the methods of subordination function and principal component analysis was used to evaluate the SO₂ resistance. Our results showed that: (1) there was the phenotypic injury with the different extents among three plant species under SO₂ stress. The chlorophyll and leaf pH declined gradually with the rise of SO₂ concentrations among three species, while the content of MDA and the relative electrolyte leakage rose. Meanwhile the soluble sugar and the proline were accumulated substantially. Furthermore, the superoxide dismutase (SOD) and catalase (CAT) were activated dramatically. (2) Through the subordination function and principal component analysis, we concluded that the resistance to SO₂ among these three species is ordered in sequence from high to low as O. japonicus > H. ventricosa > S. stolonifera, which is opposite as the order of phenotypic injury and leaf pH value. (3) The purification ability to SO₂ is ranked in order from high to low as S. stolonifera > O. japonicus > H. ventricosa. The results showed that all the three shadetolerant groundcover plants could increase their protective enzyme activities and osmotic adjustment substance contents under SO₂ stress, enhance their resistance to sulfur stress and SO₂ uptake capacity, and O. japonicus had the strongest resistance to SO₂, S. stolonifera had the strongest absorption capacity on SO₂; the lowest concentration of SO₂ in this experiment is much higher than the actual concentration of SO₂ in the urban atmosphere, in which the three shade plants are not present in the injury symptoms, so healthy and strong absorption of sulfur of S. stolonifera and O. japonicus can be used in SO₂ heavily polluted areas.