This antifouling coating composition contains a silyl acrylate based copolymer which comprises (1) component units derived from triisopropylsilyl methacrylate (i) (2) component units derived from triisopropylsilyl acrylate (ii) and (3) component units derived from a polymerizable monomer (iii) having a polymerizable double bond said silyl acrylate based copolymer satisfying specific requirements. Thus an antifouling coating composition which exhibits excellent long term storage stability and which when formed into a coating film exhibits excellent long term antifouling properties and excellent long term water resistance can be obtained.
