PURPOSE: To prepare the cultured laver disease injury-controlling agent containing glutaric acid as an active ingredient and capable of simultaneously performing the control of various algae such as green laver and the control of adhered bacteria such as red rot bacteria and pot-like bacteria without injuring the laver.

CONSTITUTION: This agent for controlling the disease injuries of the cultured laver contains (A) a glutaric acid aqueous solution (including sea water) in a concentration of 0.01-2.0 (vol./wt.)%, and preferably further (B) one or more kinds of compounds selected from the group of adipic acid, succinic acid, acetic acid, mono-, di- and trichloroacetic acids, citric acid, gluconic acid, fumaric acid, formic acid, lactic acid, ketoglutaric acid, phytic acid, phosphoric acid, hydrochloric acid, tartaric acid, sulfuric acid, nitric acid, maleic acid, and malic acid in a concentration of 0.01-0.3%, the concentrations being corresponding to required treating times, respectively. The cultured laver is immersed in or sprayed with the solution of the disease injury-controlling agent to control various algae contained in the cultured laver and the disease injuries of the cultured laver.