Abstract:Populus euphratica Oliv.、Alhagi sparsifolia B.Keller et Shap.、Tamarix ramosissima Lbd. and Calligonum caput-medus ae Schrenk., are all constructive plants in Taklamaka Desert. Responses of pho tosynthetic parameters of the four desert plants to changes light intensity and CO 2 concentration were studied, the results are as follows:①Among the four p lants, A. sparsifolia has the highest photorespiration rate (R p) and C O 2 compensation point(Γ), and it has the lowest maximal net assimilation rate(A ...