A resin composition comprises (A) 100 parts by weight of cyanate ester resin; (B) 5 to 25 parts by weight of nitrogen and oxygen containing heterocyclic compound; (C) 5 to 75 parts by weight of polyphenylene oxide resin; and (D) 5 to 100 parts by weight of oligomer of phenylmethane maleimide. By using specific components at specific proportions, the resin composition of the invention offers the features of low dielectric constant and low dissipation factor and can be made into prepreg that may be used in printed circuit board.