To provide a system and method for preserving cut flowers, capable of reducing water renewing frequency by reusing water in a water tank for dipping the cut flowers, and workable by combinedly making the activity of giving an agent for keeping freshness to the cut flowers and giving a nourishment supplying agent to the cut flowers.

This system and method comprises drawing up water, with a pump 42, in water tanks 13a and 13b dipping the cut face of cut flowers 35, sterilizing the water in a sterilizing vessel 44 by irradiating the water with ultraviolet rays, then filtrating the sterilized water with a hollow fiber membrane 45a, cooling the filtrate water and returning the water to the water tanks 13a and 13b. Proliferation of bacteria is suppressed thereby, vessel blockage of the cut flowers caused by bacteria is prevented and freshness of the cut flowers can be kept. The water in the water tank 13a and 13b can be repetitively used.