To provide an anticlouding coating agent excellent in storage stability, free from stickiness problem, giving excellent anticlouding effect immediately after coating and having a sustained anticlouding effect.

This anticlouding coating agent is a composition comprising 0.1-20 pts.wt. of a colloidal alumina (A), 0.1-20 pts.wt. of a colloidal silica (B), and 0.1-10 pts.wt. of a water-soluble resin (C), based on 100 pts.wt. of water, wherein the average molecular weight of the water-soluble resin is 100,000-4,000,000, and (C)/((A)+(B)) is 0.01-0.5.