Abstract: In order to decrease the chemical reactivity and viscosity of E51 epoxy resin,an active diluent was added to E51 epoxy on a certain mass concentration and some modified amine hardener was incorporated into the low molecular polyamide hardener during preparation of bisphenol A epoxy resin based VARTM resin. The technological properties of VARTM resin and mechanical behaviors of the cured resin with different active diluent contents were investigated in this paper. The experimental results showed that reducing the content of low molecular polyamide and increasing the content of modified amine to some extent can effectively lower the low temperature reactivity of resin system.In addition,both the viscosity of the resin and the mechanical properties of the cured resin are affected by active diluent content.