PURPOSE: To obtain a solid activator for a cut flower, capable of improving keeping quality of a cut flower by application to water and having a life- prolonging effect on a cut flower.

CONSTITUTION: This solid activator for a cut flower is characteristically composed mainly of an aqueous solution containing 10 to 95wt.% water containing 0.1 to 20.0wt.% alkaline metal salt or alkaline earth metal salt of hypochlorous acid and having pH7.5 to 12.0 and 5 to 90wt.% Japanese rice wine or beer and has a solid state in which it is supported in an amount of ≥10wt.% based on the tare weight.