The genetic characteristics of a plant's long-term adaptation to the environment have important influences on photosynthesis and growth. To understand the mechanism of Caryopteris mongholica photosynthetic response to climate variation, this study measured the light response curve of Caryopteris mongholica from eight places of origin in the same environment, and compared the differences in their photosynthetic response parameters and the climate effects on their photosynthetic characteristics. The results showed that:(1) In the same environment, the photosynthetic capacity of Caryopteris mongholica was related to its provenance. The photosynthetic capacity of Caryopteris mongholica gradually decreased along geographical gradients from east to west and north to south, and the maximum net photosynthetic rate (P_nmax) of plants from Sonid Left Banner and Erlianhot were greater than those of the rest of the origin locations, and the minimum of P_nmax was in plants from Gansu Minqin. (2) The climate of the location of origin had a significant impact on photosynthetic characteristics of Caryopteris mongholica, and the temperature and altitude were the main factors. (3) The explanatory power of the climate factor for each photosynthetic characteristic was between 16.65% and 73.52%. It had a significant impact on α₁, P_nmax, Ic, and Rd, and explained at least 40% of each of these. It can be observed that the different climate in different locations is one of the most important factors that caused the variations in the light response characteristics in plants from these different places, and the differences in the photosynthetic capacity of Caryopteris mongholica from different provenances are the embodiment of its adaptation to unique environments.