Abstract:It is important to study photosynthetic characteristics and micro-environmental constraints of Paeonia ostii and Paeonia rockii for the cultivation and promotion of oil peony. We selected P.ostii(Tongling, Anhui) and P.rockii(Lanzhou, Gansu) to measure the photosynthetic characteristics and micro-environmental factors, and analyzed photosynthesis limiting factors. At Phoenix Mountain (Tongling, Anhui), leaf temperature was the main limiting factor of photosynthesis in high temperature and drought seasons. When the temperature reached 31℃, the respiration rate was inhibited, and when the temperature reached 32℃, stomatal conductance and photosynthetic rate were reversed, and when the temperature reached 33 degrees, physiological damage appeared. At Gansu zhongchuan peony garden, the relative humidity was the most important influencing factor of photosynthesis characteristics, which determined the light saturation point, stomatal conductance, transpiration rate and water use efficiency of P.rockii. An appropriate shade habitat of the forest edge or forest gap is the most suitable environment for the growth of P.ostii and P.rockii.