The present invention provides: a granular hydrating agent which has both a high initial activity and a high residual activity and can retain excellent disintegrativity and dispersibility even after being stored for a long period； and a method for producing the granular hydrating agent. The granular hydrating agent according to the present invention comprises aggregates, wherein each of the aggregates comprises: a fine powder of an agrochemical active component, said fine powder having a 50% particle size of 0.1 to 5 μm in a volume-based cumulative particle size distribution； a coarse powder of an agrochemical active component that is the same as the above-mentioned agrochemical active component, said coarse powder having a 50% particle size of 2 to 20 μm in a volume-based cumulative particle size distribution； and a carrier composed only of a poorly hygroscopic water-soluble powder.
