To provide a deodorant which has swellability and water holding property, prevents root rot and enables the dedorization of the place of use by dissolving a high-polymer compd. contg. potassium and tropolone into water, thereby constituting the deodorant.

This deodorant is prepd. by adding about 5 to 8g potassium propenoate propenamite copolymer and about 6 to 10cc hinokitiol to about 50cc water, mixing the mixture and stirring the mixture for about 80 to 130min under a normal temp. environment. This deodorant exhibits a humid block-like form and deep green color and may be made into desired colors by edible dyestuff. The deodorant is used by laying the deodorant at about 2 to 3mm thickness on the soil of an indoor flower pot for ornamental plants, etc. The deodorant is otherwise usable as a medium for water culture cultivation of seeding, etc., by laying the deodorant in a water-resistant vessel. The potassium propenoate propenamite copolymer of such constitution has a property to swell in the presence of water and to hold the water and is, therefore, iteratively usable by applying the water thereto. Since the copolymer contains the potassium, the deodorant acts as a fertilizer as well and allows deodorization and plant growth.