Curing behavior and processing of a novel BMI resin ( R801) for RTM were investigated. The mechanical properties. Carbon fiber reinforced BMI composites were also studied. DSC results indicated that the curing temperature of this resin ranged from 170℃ to 220℃. There is a low viscosity platform longer than 7 hours due to the soft rise of the resin’s viscosity from 70 to 120℃ the viscosity-to-temperature curves. Sufficient processing time longer than 10 hours is possible with the initial viscosity below 100 mPa·s at the temperature about 90℃. According to the testing mechanical properties,excellent heat-resistant property could also be obtained for the composites using it as the matrix,and mechanical properties retention is above 63% when tested at 300℃.