Resin matrixes for aeronautic advanced composites based on thermoplastic PEK-C (modified polyetherketone) and blending epoxies of DGEBA (diglycidyl ether of bisphenol A) and TGMDA (tetraglycidyl methylenedianiline) are analyzed by DMTA in this paper. The effects of blending ratios and high-temperature post-curing processes on DMTA properties are investigated. The results show that epoxies exhibit different curing features with the existence of high viscous thermoplastic, by contrarily the neat epoxies systems cure according to a random copolymerization rule. The primary peak of tangent delta of DMTA mainly attributes to segment motions of thermoplastic in a blend and the secondary peak mainly for those of the DGEBA cured networks. The higher the ratio of TGMDA to DGEBA is the more obviously the separation degree of tangent delta peaks adopt. Increasing the amount of TGMDA is helpful for separating of phases in the blends. High temperature post-curing promotes separating of phases. In a blend the continuous phase mainly consists of a mass of thermoplastic and some TGMDA, DGEBA mainly collects in dispersed phases.