Abstract: In order to study the effects of drought stress on the morphology and physiological indicators of Lotus japonicus and understand its drought resistance performance in Guizhou region, five treatments were set up, namely P1（6% polyethylene glycol-6000）, P2（12% polyethylene glycol-6000）, P3（18% polyethylene glycol-6000）, P4（24% polyethylene glycol-6000） treatment and blank control（CK, Hoagland nutrient solution prepared with purified water） treatment. Each treatment had 15 bottles, and lotus japonicus at the seedling stage was subjected to drought stress.The morphological and physiological indicators of Lotus japonicus were determined after 30 days of stress. The principal component analysis and fuzzy membership function were used to comprehensively evaluate the Lotus japonicus under different polyethylene glycol-6000 concentrations. The results showed that with the increase of drought stress, the plant height, root length, rhizosphere diameter, stem diameter, aboveground fresh weight, underground fresh weight, and single plant fresh weight of Lotus japonicus generally decreased first and then increased and then decreased. Among them, the root length, rhizosphere diameter, and stem diameter in the P2 treatment were the largest, and the differences in plant height and root volume among different treatments were not significant（P＞0.05）. The plant height in the CK treatment was the highest, while the root volume in the P3 treatment was the largest. The aboveground fresh weight was the highest in the CK treatment, and the underground fresh weight in the P2 treatment was the highest and significantly higher than that in the CK, P1, P3, and P4 treatments（P＜0.05）. With the increase of drougth stress, the main root activity showed a trend of first increasing and then fluctuating decreasing, while the fibrous root activity showed a trend of first decreasing, then increasing and then decreasing. The leaf chlorophyll content showed a trend of fluctuating increasing and then decreasing, while the stem chlorophyll content showed a continuous upward trend. Among them, the main root activity in the P1 treatment was the highest, the fibrous root activity in the P2 treatment was the highest, and the leaf chlorophyll content in the P3 treatment was the highest, which were significantly higher than those in the CK, P1, and P2 treatments（P＜0.05）. The stem chlorophyll content in the P4 treatment was the highest, which was significantly higher than that in other treatments（P＜0.05）. With the increase of drougth stress, the protein content, malondialdehyde（MDA） concentration, proline mass（PRO） concentration, superoxide dismutase（SOD） activity, and catalase（CAT） activity in the leaves and stems generally showed an fluctuating upward trend. The peroxidase（POD） activity in the leaves showed a trend of first increasing and then decreasing, while that in the stems showed a trend of first decreasing and then increasing. The content of ethylene（1-aminocydopropane-1-carboxylic acid, ACC） showed a fluctually decreasing trend, while the content of abscisic acid（ABA） showed a gradually increasing trend. The contents of salicylic acid（SA）, 3-indoleacetic acid（IAA） showed a trend of first increasing and then decreasing, the contents of free cytokinin（CTK）, jasmonic acid（JA） and its derivatives, and gibberellins（GAs） were increased. According to the comprehensive evaluation value, the ranking of the five treatments from large to small was P3＞CK＞P1＞P4＞P2. In P3 treatment, there was no significant difference in plant height, rhizosphere diameter, stem diameter, root volume, and branch number compared to CK treatment（P＞0.05）, while root length, aboveground fresh weight, underground fresh weight, and single plant fresh weight were significantly lower than CK treatment（P＜0.05）, ranking before CK treatment. The results indicated that drought stress had an impact on the morphology and physiological indicators of Lotus japonicus, and the physiological indicators were more responsive to drought stress than agronomic traits.