Perennial ryegrass (Lolium perenne L.), widely used in temperate climates, is one of turf grasses that enrich cadmium (Cd). The objective of this study was to explore the physiological responses and candidate gene expression in perennial ryegrass to Cd stress. Grasses were subjected to three levels of 0, 0.2, and 0.5 mM Cd for 7 days in the greenhouse. The results indicated that soluble protein content was lower in the Cd-treated perennial ryegrass compared to untreated plants. The Cd-treated perennial ryegrass exhibited a greater level of malondialdehyde and activity of the peroxidase (POD), catalase, and superoxide dismutase (SOD) relative to the control. The Cd stress induced up-regulated expression of FeSOD, MnSOD, Chl Cu/ZnSOD, Cyt Cu/ZnSOD, APX, GPX, GR and POD at 4–24 h after treatment began for perennial ryegrass. Results suggested that the gene transcript profile was related to the enzyme activity under Cd stress.