The invention relates to an
epoxy resin composition and a high-frequency circuit board manufactured thereby. The
epoxy resin composition comprises the following
solid components: (A)
cyanate compound or
prepolymer thereof, wherein the molecule of the
cyanate compound contains at least two cyanato groups; (B) active ester; and (C)
epoxy resin containing a naphthol structure; calculated in
solid component in parts by weight, the total amount of the component (A), i.e. the
cyanate compound containing at least two cyanato groups in the molecule thereof or the
prepolymer thereof, and the component (B), i.e. active ester, is 10-70 parts by weight, and the amount of the component (C), i.e. epoxy resin containing naphthol structure, is 30-90 parts by weight, wherein the weight ratio of the component (A), i.e. the
cyanate compound containing at least two cyanato groups in the molecule thereof or the
prepolymer thereof, to the component (B), i.e. active ester, is (0.2-5):1. The high-frequency circuit board manufactured by using the epoxy resin composition of the invention comprises a plurality of
layers of prepregs which are overlapped mutually, and
copper foils which are compressed on the two sides respectively; and each of the plurality of
layers of prepregs comprises a base material and the epoxy resin composition which is adhered to the base material through impregnation and
drying.