Abstract: （OBJECTIVE）Study on the photosynthesis and fluorescence characteristics in peony under gradually drought,（METHOD）The photosynthesis and fluorescence characteristics of peony varieties Hu Hong and Luoyang hong，soil gradually drought, the photosynthetic response from the peony, gas exchange, chlorophyll fluorescence to study the changes in photosynthesis and Peony fluorescence characteristics. （RESULTS）With the increase soil moisture stress, leaves the net photosynthetic rate (Pn) and stomatal conductance (Gs) decline in intracellular CO2 concentration (Ci) increased drought reduced Peony net photosynthesis, gas exchange restrictions. （CONCLUSION）75 percent of the soil moisture content best suited to the relative growth of the peony, also found that compared with the drought stress, too much moisture Peony more negative growth. Comparison between the different species found, Hong Hu Hung more drought-tolerant than in Luoyang, wider adaptability．