Abstract: Nowadays, the agricultural production is still restrited greatly by the natural circumstances This article suggests that it is necessary to establish a favourable eco-environment firstly. Take Ka Zuo county of Liaoning province as an example. The main measures are:1. To strengthen resource protection and prevent deterioration of eco-environment;2. To strengthen the investigation of natural resources and the overall agricultural regionalization;3. To combine the engineering construction with the biological practices;4. To improve and enhance soil fertility and establish a stable and high-productive farm environment.5. To regulate the cropping system and the productive structure.

Key words: Pinus koraiensis, Elevated CO₂, Net photosynthetic rate, Stomatal conductance, RuBP, Soluble sugar, Chlorophyll