Abstract: In order to compare the Red clover (Trifolium pretense) drought resistance, the effects of PEG stress on physiological and biochemical indexes of four Red clover accessions and one Red clover variety leaf were investigated under treatments with different PEG concentrations. Wuxi Red clover, with the higher relative water content and least decreasing changes, a decline of 28.49% compared with the control, the lowest electrical conductivities, increased by 2.78 times compared with the control, and the smallest increasing rates of MDA contents, increased by 2.84 times compared with the control under 20% PEG stress had more tolerant membrane systems and was the most resistant to osmotic stress, while Red clover 06-4 was relatively weaker resistant. Proline accumulation in leaves of five red clovers had the strongest resistance under PEG stress, and proline accumulation content of Wuxi Red clover was 30.84 times to the control group. SOD activities in leaves of five accessions increased during the initial stress stage at 5% PEG concentration and decreased continuously under severer stress. PEG stress resulted in the decreases in leaf relative content and increases in leaf cell membrane permeability, MDA content and praline accumulation of five Red clover wild accessions. SOD activities decreased continuously under severer stress. There was difference in the changing extents of the corresponding indices among five Red clovers. Red clover Wuxi was the most resistant to osmotic stress, while the resistance of Red clover 06-4 was the weakest.