Silicone-modified styrene-butyl acrylate copolymer latex was synthesized by emulsion copolymerization by using octamethylcyclotetrasiloxane (D-4), styrene, and butyl acrylate as raw materials, potassium persulfate as initiator and propylmethacrylate triethoxysilane (KH-570) as crosslinking agent. The infrared spectra studies showed that the vinyl monomers were completely copolymerized with D-4. The prepared silicone-modified copolymer latex with the interpenetrating polymer networks tended to have higher stability, and better toluene and water resistance than styrene-butyl acrylate latex. The glossiness of coated paper was improved with silicone-modified copolymer latex, and it was at a maximum when D-4 was about 3% of total monomers.