The present invention provides a method for controlling weed in wet rice cultivation, which comprises: a step wherein an aqueous diluted solution that contains a herbicidal compound such as 1-(2-chloro-6-propylimidazo[1,2-b]pyridazin- 3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2-yl)urea is sprayed over a rice field； and a step wherein the rice filed is flooded within a week after the treatment with use of the herbicidal compound.
