Halogen-free resin composition, prepreg, and laminate for printed circuits. Based on 100 parts by weight of organic solid matter, it comprises: (A) dicyclopentadiene-type benzoxazine resin: 50-80 parts by weight; (B) dicyclopentadiene-type epoxy resin; (C) dicyclopentadiene-type novolac hardener; (D) phosphorus-containing flame retardant. The dicyclopentadiene structure in (A) decreases the dielectric constant, dielectric dissipation value, and water absorption of cured products and maintain adhesive force as the main resin; adding (B) can improve the tenacity of cured products and maintain low water absorption and excellent dielectric performances; Taking the dicyclopentadiene-type novolac as the hardener can sufficiently exert the advantage of excellent dielectric performances and good thermal and moisture resistance resulted from the dicyclopentadiene-containing structure. The prepreg above and the laminate for printed circuits using the prepreg have low dielectric constant, low dielectric dissipation factor, low water absorption, high adhesion, high thermal resistance and good flame retardancy, processability and chemical resistance.