Abstract: In the present study, the effects of 200 mg/L carboxymethyl chitosan（CMCS） and 20 mg/L nano-silver（NS） additions in basic preservation liquid（CK2, 3% sucrose+200 mg/L citric acid+25 mg/L salicylic acid） on ornamental qualities and post-physiological characteristics of P. lactiflora cut flowers were investigated using distilled water as control（CK1）. Results showed that both of CMCS and NS treatments could improve the water balance of cut flowers and enhance the ornamental qualities. Compared with the control（CK1）, the maximum flower diameters of P. lactiflora cut flowers after CMCS and NS treatments were increased by 2.17 cm and 3.19 cm, respectively, and the vase lives were prolonged by 3.01 d and 4.26 d, and the best viewing periods were prolonged by 1.87 d and 2.75 d. Besides, CMCS and NS treatments presented similar regulatory effects on the physiological characteristics of P. lactiflora cut flowers via improving soluble protein contents, enhancing superoxide dismutase（SOD）, peroxidase（POD） and catalase（CAT） activities, and decreasing the relative conductivity, malondialdehyde（MDA） and free proline（Pro） contents, moreover, the 20 mg/L NS treatment showed the best preservation effects.