In this paper,diurnal dynamics of photosynthesis physical-ecological characters,P_n-PAR and P_n-C_i response curves were measured,and the relationship between P_n and main ecological factors was analyzed in three young sandy plants seedlings.The results showed that:(1)Diurnal dynamics curves of net photosynthetic rate(P_n) of Morus alba,Apocynum lancifolium and Atraphaxis bracteata appeared “bimodal-peak”,“single-peak” and “continued to decline” types,respectively.(2)Water utility efficiency(WUE) and light utility efficiency(QUE) of A.bracteata was higher than that of A.lancifolium and M.alba’s.M.alba has a strong ecological adaptation range for light intensity,the range of using light intensity of A.lancifolium is relatively narrow,so photosynthetic potential is not high.The maximum net photosynthetic rate(P_max) of A.bracteata was the highest,which suggested its photosynthetic capacity was higher also,A.lancifolium has the highest CO₂ compensation point(CCP) and saturation point(CSP),at the same time,with smaller P_max.(3)The atmospheric temperature(T_a) has greater direct and indirect impact on P_n of M.alba and A.lancifolium,and vapor pressure deficit(VPD) coupling T_a had larger indirect effects on P_n of A.bracteata and A.lancifolium.To sum up,in terms of photosynthetic physiological adaptability.As preventing and desertification controling plant material,A.bracteata can be planted in the sandy slope with full light,M.alba in the transition zone of oasis and desert afforestation,and A.lancifolium in the sandy slope with weak light condition.