Abstract: An attempt was made to determine the vase life of spray type carnation flowers by observing the number of open flowers, i.e. the percentage of open flowers to the total number of initial flower buds, and to evaluate the efficacy of this method. The vase life determined by this method was similar to that determined by measuring ethylene production and observing senescence symptoms of carnation flowers. The method effectively evaluated the action of preservatives, sucrose and 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide in carnation flowers. The results indicated that this method can be used as an alternative method for the determination of the vase life of carnation flowers, especially those of the spray type.