A resin composition includes (A) an epoxy resin; (B) a benzoxazine (BZ) resin; (C) a styrene maleic anhydride (SMA) copolymer; and (D) a polyester. The resin composition includes specific ingredients of a polyester and is characterized by specific proportions thereof so as to achieve a low delta Tg value of copper clad laminates manufactured in accordance with the resin composition and attain a low dielectric constant, a low dielectric dissipation factor, high heat resistance, and high fire retardation of the copper clad laminates and printed circuit boards manufactured in accordance with the resin composition.