Abstract: In order to reveal the ecological adaptation of typical pioneer woody plants (Ailanthus altissima, Robinia pseudoacacia, Vitex negundo L. var. heterophylla，Hippophae rhamnoides and Amorpha fruticosa) in the mining areas of the Loess Plateau, this paper analyzed the photosynthetic characteristics of these five plant seedlings under different light intensity and CO₂ concentration conditions by using Li- 6400XT portable photosynthesis system based on greenhouse soil culturing experiment. The results showed that the modified rectangular hyperbola model could better fit the light and CO₂ response curves. Firstly, the indexes of these five plant seedlings such as Pmax, AQY, Rd, LSP, LCP, Amax, CE, Rp, CSP and CCP presented significant difference (P＜0.05). The indexes of Pmax, Amax, CE, Rd and Rp about Hippophae rhamnoides were significantly higher than that of the other four plant seedlings and the indexes of LSP and LCP were significantly higher than those seedlings of Robinia pseudoacacia, Amorpha fruticosa, and Vitex negundo (P＜0.05). Hippophae rhamnoides seedlings could better adapt to different light intensity and CO₂ concentration conditions, and contained stronger photosynthesis producing and breathing potential. Secondly, the indexes of Pmax and AQY of Ailanthus altissima seedlings were significantly lower than that of the other four plant seedlings, and its LSP and LCP were higher than those seedlings of Robinia pseudoacacia, Amorpha fruticosa and Vitex negundo L. var. heterophylla. Ailanthus altissima seedlings had weak shade tolerance and photosynthetic capacity, and failed to take advantage of weak light. Thirdly, the Amax of Amorpha fruticosa and Robinia pseudoacacia seedlings were significantly lower than that of the other three plant seedlings and contained lower photosynthetic potential. Finally, the increase of CO₂ concentration was conducive to the improvement of water use efficiency of these five plant seedlings. As a result, it is important to conduct reasonable allocation referring to their ecological adaptability to the light and CO₂ concentration in the practice of ecological restoration in mining areas of the Loess Plateau.