Global climate change could exacerbate biological invasions by changing competitive interactions, and hence, threaten ecosystem biodiversity and stability. Replacement control, which relies on the growth advantage of native plants, is one of the most effective methods to suppress invasion. In the present study, distinctive photosynthetic responses to warming of invasive (Alternanthera philoxeroides) and native (Sambucus chinensis) plants were compared to determine the invasive potential of alien plants, and to screen native species for replacement control under climate change scenarios. Plants were grown in two different air temperatures (unwarmed or ambient temperature and warmed at (0.76±0.10)℃ by using an infrared heater) for a 5-month short-term period, and photosynthetic pigment concentrations and gas exchange characteristics were determined. The results showed that warming significantly and positively improved the chlorophyll a/b ratio by 6.21% in A. philoxeroides(P < 0.01), but negatively by 5.55% in S. chinensis(P < 0.05). Meanwhile, chlorophyll b, rather than both chlorophyll a and carotenoid, was significantly higher in S. chinensis than in A. philoxeroides, at ambient (P < 0.001) and increased temperatures (P < 0.05). Increased temperatures significantly increased the net photosynthetic rate by 9.23% in A. philoxeroides(P < 0.01), but decreased the water use efficiency by 10.64% (P < 0.01) due to a respective increase in stomatal conductance by 11.10% (P < 0.05) and transpiration rate by 21.46% (P < 0.001). In contrast, increased temperatures significantly enhanced stomatal conductance by 10.95% in S. chinensis(P < 0.001), but had no effect on other gas exchange traits. Under the control conditions, the stomatal conductance and intercellular CO₂ concentration were 7.03% (P < 0.05) and 4.57% (P < 0.001) higher, but the net photosynthetic rate and water use efficiency were 10.30% (P < 0.001) and 11.92% (P < 0.05) lower in A. philoxeroides than in S. chinensis, respectively. However, under increased temperatures no significant differences in net photosynthetic rate and stomatal conductance were observed between the two plant species. In contrast, under increased temperatures, water use efficiency was 26.45% higher in S. chinensis than in A. philoxeroides(P < 0.001), possibly because of lower transpiration rates in S. chinensis. Increased temperatures, species, and their interactions did not have significant effects on photosynthetic-light curve parameters. In general, S. chinensis had a stronger photosynthetic capacity than the invasive A. philoxeroides in terms of chlorophyll b content, net photosynthetic rate, and water use efficiency, especially in control conditions. However, the photosynthetic advantage of S. chinensis was eliminated with increased temperatures. Collectively, our results suggested that S. chinensis could potentially be used in ecological restoration to replace A. philoxeroides in invaded habitats.