【Abstract】The objective of the current study was to screen the optimum concentration of brassinosteroid （BR） to improve chilling resistance of bitter gourd seedlings in order to lessen the losses caused by low temperature stress. 【Method】The plant growth indices， metabolites， viz.， MDA and soluble sugar content， relative conductivity， and activities of peroxidase （POD） and superoxide dismutase （SOD） enzymes in the leaves were investigated in bitter gourd seedlings treated with different concentrations of BR （10-4，10-3，10-2，10-1 and 10 mg/L） under the conditions of low temperature （8.0±0.5℃） stress for 72 h， CK1 （normal temperature） and CK2 （low temperature stress） were set as controls. 【Result】Different concentrations of BR treatment promoted the growth of bitter gourd seedlings and decreased the chilling effects （chilling index） by increasing the fresh weight， the contents  of chlorophyll， soluble protein， proline， and the activities of POD and SOD enzymes， reducing the accumulation of MDA and decreasing the relative conductivity significantly， compared to CK2. 【Conclusion】BR treatment with different concentrations could significantly enhance chilling resistance of bitter gourd seedlings， however， the best seedlings growth was observed in the treatment 10-2 mg/L concentration of BR.