Cut rose (Rosa hybrida L.) ‘Sonia’ flowers were placed in vases of which water temperatures were kept at 10, 15 and 23°C under constant air temperature of 23°C. Vase life of cut roses became longer with lowering water temperature; the vase life was 5.2, 6.7 and 7.5 days at 23, 15 and 10°C, respectively. Fresh weight of cut flowers increased over the first 3, 4 and 5 days during the experimental period at 23, 15 and 10°C, respectively and decreased thereafter. Temperature of flower part was very slightly lowered by lowering water temperature. Hydraulic conductance of stem segments decreased on the third day after harvest, and this decrease was suppressed by lowering the temperature of vase water. Bacterial number in vase water increased with time, and this increase was suppressed by lowering the temperature of vase water. These results show that low temperature of vase water might improve the stem water relation and extended the vase life of cut rose flowers.