the invention provides a dielectric material with low dielectric loss . the dielectric material comprises 40 ˜ 80 parts by weight of polyphenylene ether resin having a mw of 1000 ˜ 7000 , a mn of 1000 ˜ 4000 and mw / mn = 1 . 0 ˜ 1 . 8 ; 5 ˜ 30 parts by weight of bismaleimide resins ; and 5 ˜ 30 parts by weight of polymer additives , wherein the dielectric material has dk of 3 . 75 ˜ 4 . 0 and df of 0 . 0025 ˜ 0 . 0045 . the dielectric material is suitably used in prepregs and insulation layers of a circuit board , because it has high tg , low thermal expansion coefficient , low moisture absorption and excellent dielectric properties such as dk and df .