The toughness index and residual strength index of aged and un aged specimens were calculated and compared according to the methodology of flexural toughness evaluation in ASTM C1018—97. The flexural behavior and durability of glass fiber chopped strand mat reinforced mortar were examined on the basis of toughness index, residual strength index, failure patterns of specimens and load deflection curves of flexural behavior test. The test results show that glass fiber chopped strand mat distributed in the tension zone of the specimens makes specimens have good flexural behavior and toughness. The aging effect can reduce the flexural strength and toughness of glass fiber chopped strand mat reinforced mortar. The higher the content of zirconium dioxide in the chopped strand mat, the weaker the influence of aging effect on reducing the flexural strength and toughness of specimens.