Abstract: A method of fabricating glass fiber/epoxy matrix composites with low sectional electrion and dielectric loss has been introduced.The composite was fabricated by using the special equipment and process and tested by using the instruments of sectional electrion and dielectric loss bridge,all made in German,in accordance with GB7354-87 and GB1408-76 respectively.The results show that the solidified composite has properties of low sectional electrion(less than 2pc)and low dielectric loss tangent(less than 0.01)and the chief reasons of successful experiment have been also discussed.At present,this method has been used in production.