We investigated the effects of paclobutrazol (PP₃₃₃) on the chlorophyll, photosynthetic parameters, nonstructural carbohydrates (NSC), C/N ratio, root activity on one-year-old phyllostachys edulis seedlings. Experiments were degined with three water treatments (W1:well-watered with 75% field capacity; W2:water stress with 50% FC; W3 water stress with 35% FC) and two levels of PP₃₃₃ treatments (P1:0mg/L; P2:40mg/L). Results showed that:as the drought increased, leaf color of P. edulis seedlings gradually faded and the concentration of Chla, Chlb, Car, Chla/b and total chl significantly decreased(P < 0.05), Pn, Tr and WUE significantly decreased (P < 0.05), Ls significantly increased (P < 0.05), the NSC content in the leaf and root significantly increased (P < 0.05), root activity significantly decreased (P < 0.05). When PP₃₃₃ was applied, the chlorophyll content were significantly increased under both P2W2 and P2W3 treatments relative to P2W1 treatment, but no significant difference was found between P2W2 and P2W3. Also, P2W3 significantly increased Pn by 146.9% compared with P1W3 treatment, and the total soluble sugar content significantly increased up to 3.41mg/g. Besides, P2W3 significantly increased the total soluble sugar content and the starch content in leaf and root, and root:shoot ratio was significantly increased. Our study demonstrated that PP₃₃₃ application could effectively improve the drought adaptability of P. edulis seedlings by increasing the root activity and root:shoot ratio, reducing water loss and NSC content, and improving the photosynthetic pigments and photosynthetic capacity.