Abstract: This study investigated the effects of gibberellin concentrations on seed germination and seedling growth of tall fescue (Festuca arundinacea) under drought stress. The seed germination experiment was conducted at 5 polyethylene glycol (PEG) levels (0%, 5%, 10%, 15% and 20%) after soaking seeds in 5 gibberellin concentrations (0,100, 200, 300 and 400 mg/L). The malondialdehyde concentration (MDA) and electrical conductivity of seeds were determined before germination, then the seedling growth, seed germination rate and potential were measured during germination. The electrical conductivities of seeds soaked in 0 and 100 mg/L gibberellin were significantly (P≤0.05) higher than those of seeds soaked at the other three gibberellin concentrations, and MDA concentrations of seeds soaked with 0 and 100 mg/L gibberellin solution were significantly lower (P≤0.05) than those of seeds soaked at the three higher gibberellin concentrations. Compared to seeds soaked in pure water, the 5% and 10% PEG treatments had, respectively, 47.06% and 37.33% greater germination potential, and 19.46% and 16.95% higher germination rate. However, the germination rate, and root and bud length were obviously decreased when the PEG concentration was 15% or higher. After soaking in 200 mg/L gibberellin solution, root length was increased 53.26%, 30.12% (compared with soaking in pure water) and the corresponding increases in bud length were 79.87% and 50.75% at 5% and 10% PEG solutions. The effect of gibberellin decreased with increase in PEG level. The inhibition of PEG stress on bud length was stronger than on root length, but the root length: bud length ratio was obviously decreased water after gibberellin treatment, compared to that of seeds soaked in pure. In summary, the optimum gibberellin concentration for enhancing the seed germination and seedling growth of tall fescue under drought stress was 100-200 mg/L.