Abstract: To evaluate the waterlogging tolerance of different Chieh-qua (edible bitter melon) varieties, waterlogging stress treatments were applied to 29 Chieh-qua varieties. The following growth and physiological indicators were measured including the number of adventitious roots, chlorophyll a, chlorophyll b, total chlorophyll content, carotenoids, relative electrical conductivity, soluble sugar, proline, malondialdehyde, peroxidase (POD) activity, and superoxide dismutase (SOD) activity. Principal component analysis, membership function analysis and cluster analysis were used to comprehensively evaluate their waterlogging tolerance. The results showed that there were significant differences in the physiological indicators among different materials. Compared with the control, chlorophyll a, chlorophyll b, total chlorophyll and carotenoids showed a significant downward trend, while the number of adventitious roots, relative conductivity, malondialdehyde, POD activity and SOD activity showed a significant upward trend, and soluble sugar and proline increased or decreased in different degrees in different materials. The results of principal component analysis showed that the first principal component (PC₁) mainly integrated the number of adventitious roots, chlorophyll a, chlorophyll b, total chlorophyll and SOD enzyme activity, and mainly reflected the information of plant phenotype under waterlogging stress. The second principal component (PC₂) mainly integrated the relative conductivity and soluble sugar to reflect the osmotic coordination ability of plants, and the third principal component (PC₃) mainly included carotenoid content. The results of comprehensive evaluation and cluster analysis showed that 29 Chieh-qua varieties could be divided into 5 categories, among which PJ16, FJ17033, FJ17089, FJ17056, FJ2, PJ20 and FJ17079 had the best waterlogging resistance.