Plant growth is limited by nitrogen and/or phosphorus in the dry-hot valley, and the nutrient limitations may differ across soil types. Photosynthesis is the basis of plant growth and development. However, the effects of nitrogen and phosphorus on plant photosynthetic characteristics in dry-hot valley have not been reported. In this study, we planted Dodonaea viscosa, the dominate species in the dry-hot valley in different soils with different elevations in Yuanmou county and fertilized them factorially with nitrogen and phosphorus. The effects of nitrogen and phosphorus addition on photosynthetic response curve, chlorophyll content and chlorophyll fluorescence were studied, and the relationship between photosynthetic response and D. viscosa growth was discussed. The results showed that:1) photosynthetic characteristics of D. viscosa in different soils responded to nitrogen and phosphorus addition differently. The net photosynthetic rate, chlorophyll content, and PSII activity of D. viscosa were increased by nitrogen addition (+N and +NP) in dry red soil. +NP promoted the photosynthetic rate and chlorophyll content of D. viscosa in purple soil. +N reduced photosynthetic rate and PSII activity of D. viscosa in yellow brown soil, where P addition treatment (+P and +NP) increased the photosynthetic rate. 2) The responses of photosynthetic characteristics of D. viscosa to nutrient addition were depended on the type of nutrient restriction in soil. The addition of the limited nutrient could improve the net photosynthetic rate of D. viscosa. 3) The reductions of Fv/Fm caused by +P in dry red soil and +N in yellow brown soil were attributed to the reduction of Fv rather than the increase of F₀, which could relieve the damage of PSII. 4) Chlorophyll content and chlorophyll composition of D. viscosa in the three soils were significantly different. Compared with dry red soil and purple soil, chlorophyll content in yellow brown soil was significantly higher, while chlorophyll a/b was significantly lower. To sum up, the results showed that the photosynthetic capacity of D. viscosa was co-regulated by nitrogen and phosphorus, and the responses of photosynthetic characteristics of D. viscosa in different soils could enhance their adaptability to restricted nutrients and affect their growth.