Abstract: In order to choose the best parameters of tackifier in vacuum assisted resin infusion (VARI) processing, the distribution of tackifier on fabrics, effects of different addition levels of tackifier on epoxide resin and mechanical performance of composites reinforced by uniaxial warp-knitting fabrics were investigated. Effects of addition levels of tackifier on the glass transition temperature and phase configuration of epoxide resin were analyzed by differential scanning calorimetry (DSC) and scanning electron microscope (SEM). Mechanical performances of composites with various amounts of tackifier were examined. It is shown that as the addition level of tackifier increases, the glass transition temperature of epoxide resin decreases, and its phase configuration transferred from sea island structure to double continuous-phase, then, at last to phase inversion structure. At room temperature, the thickness and irregularity of tackifier on surface of fabrics were increasing with increasing tackifier. After high-temperature processing, the tackifier have uniformly distributed onto the surface of fabrics. Addition levels of tackifier have significant effects on the mechanical properties of composites. The comprehensive mechanical properties of composites reinforced by uniaxial warp-knitting fabrics reach the best when the addition level of tackifier remains at 20 g/m².