The polyacrylate-g-polysiloxane copolymers were prepared by condensation reaction of polyacrylate with polysiloxane. Nine different formulations of marine antifouling coatings based on TiO2 and polyacrylate-g-polysiloxane were fabricated. The coatings had strong adhesion to substrate due to the incorporation of main-chain acrylic moieties. The side-chain Si–O bonds from polysiloxane enable the copolymer to hydrolytically degrade, and provide a self-polishing character and the low surface energy to the copolymer coating. The performance of nine formulations was evaluated, and the Y7 coating exhibited hydrophobic, 6H pencil hardness and5B cross-cut adhesion. The properties of the Y7 coatings are substrate-independent. Antibacterial test and cytotoxicity test were conducted to verify that nano-TiO2 particles inside marine antifouling coating inhibited bacterial growth and enhanced anti-bio adhesion. The results of marine field test inartificial sea waters for six months reveal that the side-chains polysiloxane leads to a self-polishing, low surface energy surface and a better antifouling property.