Abstract: Differences of soybean yield and quality between treatments was studied by spraying different concentrations of uniconazole at the V₅ and R₁ stages. Spraying 25-100 mg/L uniconazole reduced plant height, enhanced stem diameter, and increased branch number and yield. The protein content, protein yield, and fat yield of all treatments were higher than those of the control (except A2B1). They were highest in the 75 mg/kg uniconazole treatment at the V₅ stage where they higher than the controls by 5.05%, 56.59%, and 59.15%, respectively. Spraying 75 mg/L uniconazole at the V₅ stage mainly increased yield, protein, and fat accumulation.