本文主要对辽西地区衰弱低质水土保持林的成因进行了分析 ,根据调查结果和试验提出了低产、低质、低效林诊断技术。并确定了改造原则、改造对象及改造后达到的目标 ,制定了相应的技术措施。为改造现有低价油松水土保持林提供了理论依据 This paper mainly analyzes the causes of weak and poor quality soil and water conservation forests in western Liaoning, and puts forward the diagnosis techniques of low yield, low quality and low efficiency forests based on the survey results and experiments. The principle of reconstruction, the object of reconstruction and the goals achieved after the renovation were confirmed, and corresponding technical measures were formulated. It provides a theoretical basis for transforming existing low-yield stands of soil and water conservation forests