Abstract: A plug seedling experiment was conducted to select the suitable plant growth regulator and determine its optimum concentration. Two plant growth regulators and two eggplant varieties‘( Jingqie No.1’, globe eggplant variety and‘Jingqie Heilongwang’, long eggplant variety) were used as experimental materials. The plant growth regulators were paclobutrazol and mepiquat chloride, and the concentration of paclobutrazol was 100 and 150 mg/L, while the concentration of mepiquat chloride was 600 and 800 mg/L. Before being sown, the seeds were socked in plant growth regulator, and the hypocotyl, plant height, biomass, G value, root activity and chlorophyll content of the plant were determined. The results showed that, compared with using mepiquat chloride, hypocotyl and plant height were reduced by using paclobutrazol. Meanwhile, the biomass of root, seedling index, G value, root activity and chlorophyll content of plant were increased by using paclobutrazol. There were more inhibition effects of the two plant growth regulators on‘Jingqie Heilongwang’ than that on‘Jingqie No.1’. In conclusion, the optimum concentration for‘Jingqie No.1’was 150 mg/L of paclobutrazol, and the optimum concentration for‘Jingqie Heilongwang’was 100 mg/L of paclobutrazol.