An antifouling coating composition comprising a hydrolyzable copolymer and an antifouling agent, wherein the hydrolyzable copolymer is at least one hydrolyzable copolymer selected from the group consisting of: a metal salt bond-containing copolymer which is an acrylic resin or a polyester resin and has a side-chain end group represented by the general formula: -COO-M-O-COR 1 [In the formula, M is zinc or copper, and R 1 is an organic group]; a metal salt bond-containing copolymer having a component unit derived from a monomer represented by the general formula: CH 2 =C(R 2)-COO-M-O-CO-C(R 2)=CH 2 [In the formula, M is zinc or copper, and R 2 is a hydrogen atom or a methyl group], and a component unit derived from other unsaturated monomer copolymerizable with the monomer; and a silyl ester copolymer having a component unit derived from a monomer represented by the general formula: R 7 -CH=C(R 3)-COO-SiR 4 R 5 R 6 [In the formula, R 3 is a hydrogen atom or a methyl group, R 4, R 5 and R 6 are each independently a hydrocarbon group, and R 7 is a hydrogen atom or R 8 -O-CO- (wherein R 8 is an organic group or a silyl group represented by -SiR 9 R 10 R 11, wherein R 9, R 10 and R 11 are each independently a hydrocarbon group)] and optionally a component unit derived from other unsaturated monomer copolymerizable with the monomer, and wherein the antifouling agent comprises at least a compound represented by the following structural formula: a metal salt bond-containing copolymer which is an acrylic resin or a polyester resin and has a side-chain end group represented by the general formula: -COO-M-O-COR 1 [In the formula, M is zinc or copper, and R 1 is an organic group]; a metal salt bond-containing copolymer having a component unit derived from a monomer represented by the general formula: CH 2 =C(R 2)-COO-M-O-CO-C(R 2)=CH 2 [In the formula, M is zinc or copper, and R 2 is a hydrogen atom or a methyl group], and a component unit derived from other unsaturated monomer copolymerizable with the monomer; and a silyl ester copolymer having a component unit derived from a monomer represented by the general formula: R 7 -CH=C(R 3)-COO-SiR 4 R 5 R 6 [In the formula, R 3 is a hydrogen atom or a methyl group, R 4, R 5 and R 6 are each independently a hydrocarbon group, and R 7 is a hydrogen atom or R 8 -O-CO- (wherein R 8 is an organic group or a silyl group represented by -SiR 9 R 10 R 11, wherein R 9, R 10 and R 11 are each independently a hydrocarbon group)] and optionally a component unit derived from other unsaturated monomer copolymerizable with the monomer, and wherein the antifouling agent comprises at least a compound represented by the following structural formula: [In the formula, R 3 is a hydrogen atom or a methyl group, R 4, R 5 and R 6 are each independently a hydrocarbon group, and R 7 is a hydrogen atom or R 8 -O-CO- (wherein R 8 is an organic group or a silyl group represented by -SiR 9 R 10 R 11, wherein R 9, R 10 and R 11 are each independently a hydrocarbon group)] and optionally a component unit derived from other unsaturated monomer copolymerizable with the monomer, and wherein the antifouling agent comprises at least a compound represented by the following structural formula: