The responsive ability and drought resistance of Urtica dioica seedlings under different soil water conditions were discussed in our study. The following bioassay parameters were investigated: the protective enzyme activity (SOD, POD), accumulations of osmolyte (soluble protein content, soluble carbohydrate content, free porline content), membrane lipid peroxidation (MDA), max photosynthesis rate and total dry tissue weight. The linear correlations of above-mentioned physiological indexes were analyzed. The seedlings of Urtica dioica were planted at 5 different soil water gradients of 9358% (control), 80.74%(T1), 67.90%(T2), 55.06%(T3) and 42.22%(T4), respectively. Our results indicated that (1) The activity of SOD enhanced with the decrease in soil water at the start, and then depressed when the soil became too dry, while the activity of POD increased all along with the decrease in soil water. The contents of soluble protein, soluble carbohydrate, free porline and MDA increased with the decrease in soil water. (2) The protective enzyme system and accumulations of osmolyte with respect to soil water content had significant negative linear correlation, while the protective enzyme system and accumulations of osmolyte with respect to MDA had significant positive linear correlation. (3) The accumulations of osmolyte with respect to total dry tissue weight had significant negative linear correlation, while there was no significant correlation between photosynthesis rate and other physiologic index.