Abstract: The types of glass fiber mats and their configuration strongly affect the melt impregnation, void content, mechanical properties of GMT sheets, and the loft ratio of sheets during the preheating process. The configuration of the snitched continuous glass fiber mat is elastic structure, and that is good for melt impregnation and elimination of the air in the sheets. The experimental results show that the snitched continuous glass fiber mat is an ideal reinforcement for GMT sheets, and it has higher permeability over the chopped and complex glass fiber mat. The sheets reinforced by the snitched continuous glass fiber mat have lower void content, and their mechanical properties are balanced.