Abstract: The effects of Trichoderma aureoviride fermentation on the growth and physiological characteristics of Trifolium repens were evaluated by seed germination in vitro and by pot experiments in a greenhouse. T. aureoviride fermentation was applied with different dilution rates and all dilution rates significantly increased the rates of seed germination, the germination index and the vigor index. The 100-times dilution had the most significant effects on seed germination rates, germination index and vigor index (94.42%, 13.42 and 9.52 respectively). In the greenhouse experiments, the fermentation of T. aureoviride with different dilution rates significantly promoted the growth of T. repens seedlings and significantly increased chlorophyll and soluble protein content, as well as the activities of antioxidant enzymes. The 100-times dilution increased T. repens root length, plant height, fresh weight, dry weight and root-shoot ratio by 37.09%, 13.18%, 57.73%, 54.35% and 20.89%respectively. It increased chlorophyll and soluble protein contents by 14.02% and 76.21% respectively, and significantly increased polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine (PAL) enzyme activities. The maximum activity of PPO, POD and PAL presented at 3 days after treatment, 1 and 4 days after treatment and 3 and 4 days after treatment, respectively. These results suggest that the fermentation of T. aureoviride has significant growth promoting effects on T. repens.