Disclosed is a sealing compound for cans, which is applied to the periphery of a can end member to seal the double-seamed portion between the can end member and a can body, said sealing compound comprising as a base component an aqueous latex of a styrene-butadiene rubber containing as a particle size-adjusting agent an alkali metal carbonate or an alkali metal salt of a phosphorus oxyacid in an amount of 0.3 to 2.0 parts by weight per 100 parts by weight of solids of the styrene-butadiene rubber.