Abstract: To investigate the synergistic effect of poly-γ-glutamic acid (γ-PGA) on different forms of nitrogen fertilizers (urea, ammonium chloride, sodium nitrate and combined application of organic and inorganic fertilizers), a pot experiment was conducted to study the effects of γ-PGA combined with different forms of nitrogen fertilizer on rape yield, quality and utilization rate of fertilizer. [Result]The results showed that the yield of rape was increased by 1.25%~26.77% under 4 forms of nitrogen fertilizer combined with γ-PGA. With 4.3 mg/kg soil of γ-PGA, the synergistic effect was better under urea and combined application of organic and inorganic fertilizers. The contents of soluble sugar, soluble protein and free amino acid were increased by 49.60%, 23.62% and 132.79% respectively, and the nitrate content decreased by 6.18%~46.08%. The synergistic effect was better under ammonium chloride and combined application of organic and inorganic fertilizers. The utilization rates of nitrogen, phosphorus and potassium were increased by 0.63%~7.61%, 0.01%~1.66% and 0.78%~6.49% respectively. The utilization rates were higher under urea and combined application of organic and inorganic fertilizers. [Conclusion]In conclusion, according to the short-term pot experiment, γ-PGA combined with urea or organic-inorganic fertilizer was recommended in agricultural production, and the dosage of γ-PGA was 4.3 mg/kg soil.