Abstract: To enhance the elasticity，toughness，and texture of cut tree peonies（Paeonia suffruticosa Andr.），the flowers were processed with high-pressure electric spraying technique，and the compound coating made of 20 g ? L-1 chitosan and 5% citric acid were applied. Then Box-Behnken center-united experiment was conducted on the basis of single-factor experiment concerning three factors including vacuum degree，nozzle diameter and spraying distance. Then the data were analyzed through the response surface regression to optimize the mechanical properties of cut tree peonies. The results showed that the optimum shape-keeping condition was vacuum 72.5 kPa，nozzle diameter 1.1 mm and spraying distance 51.2 cm. After the cut flowers were processed under this condition and stored at room temperature for one week，their tensile strength was 14.40 MPa，and puncture strength was 8.13 MPa. Compared with the control group，the method that used here could preserve the original structure of the cut tree peonies，and enhance their resistance to wear，pressure and shock significantly.

Key words: tree peony, cut flower, mechanical property, high-pressure electric spraying