Heat~treated composite materials made of various composition of nylon 6, PPTA, and modified PPTA were prepared. Heat-treatment carnied out in vacuum oven for 60min at 16$0^{circ}C$. The mechanical and structural properties of the composite materials were investigated by UTM, SEM, XRD and RV, etc. By the heat treatment, loss and storage moduli increased and moved to higher temperature region compared with the non-heat treated materials.