The diminishing availability of phosphorus (P) in soils poses a significant constraint, impacting over 30 % of global agricultural and forestry production. Root exudates play a crucial role in, helping plants cope with environmental stress and facilitating communication between plants. Conducting physiological and proteomic analyses under low P and L-arginine treatments, this study delved into the internal regulatory mechanisms of L-arginine in Chinese fir under low P conditions. Adding L-arginine not only expanded the root length and surface area but also substantially improved the P accumulate capacity of Chinese fir. Physiological examinations revealed a notable increase in peroxidase (POD) activity by 81.10 % and superoxide dismutase (SOD) activity by 31.39 % with the addition of L-arginine under low P conditions. Proteomics analysis further demonstrated that L-arginine significantly downregulated the expression of phosphate transporters (PHTs) while concurrently upregulating POD expression. The regulation extended beyond POD activity, involving the expression of anthocyanidin synthase, showcasing L-arginine's comprehensive impact on stress tolerance in Chinese fir under low P conditions. It established that the exogenous addition of L-arginine regulated the root development and enhanced P absorption and uptake. This strategic supplementation strengthens the stress resistance of Chinese fir to low P, offering valuable insights into root secretion mechanisms in response to adaptive strategies in a low P environment.