Abstract: Tetra (3ethylphenylamino)silanes (TEAS) has good performances such as simple process of synthesis, good solubility, low curing temperature and good heat resistance etc, but the mechanical strength of its composite reinforced with glass fiber is low. Di ［(Nmacetenylphenyl) phthalimide］ ether (DAIE) was used to mix with tetra (3ethylphenylamino)silanes (TEAS) with proper ratio, and the obtained resin (TEASDAIE) was used as the matrix resin of composite. The heat resistance, mechanical strength, dielectric property, water adsorption and the fracture surface of the composite were studied. The results showed that the mechanical property of the composite is very good. The flexural strength of the composite was 385.7 MPa at room temperature, while decreased to 373.1 MPa at 240 ℃ with a retention ratio of 96.7%. Its glass transition temperature is up to 362.5 ℃. The water resistance and the dielectric property of the composite were also very good. After soaking the composite in water at room temperature for 96 h, the water adsorption ratio was only 1.06%, the dielectric constant was 3.95, and the tangent for the dielectric loss angle was 5.73×10-3.