The present study developed a new type of nanofibrous structure-TiO2 nanofiber sheets (TNFS) to increase theinterlaminar fracture toughness of glass fiber reinforced polymer (GFRP) laminates. SEM was employed to characterize thenanofibers before and after calcination. In order to quantify TNFS, the thickness and the crevice area of TNFS were analyzed,the results showed that the thickness and the proportion of crevice area were increased with the increase of TNFS contents. Mode I and Mode II interlaminar fracture toughness were investigated for GFRP laminates toughened by different massfraction of TNFS. The highest Mode I fracture toughness value achieved by inserting 5 wt.% TNFS in the interleaf. GIc valuewas 74.35 % higher than those of base GFRP laminates. Meanwhile, with 6 wt.% addition of TNFS, the GFRP laminatesshowed the highest Mode II fracture toughness, which is 60.76 % higher than those of base GFRP laminates. Theimprovement mechanism of toughness was illustrated by the fracture surface analysis of TNFS interlayered laminates.