Inter layer performance enhancement with short glass fiber provides a feasible approach for improving inter layer tearing strength of glass fiber reinforced plastic (GFRP) composites. The effects of laying short glass fiber (SGF) between two layers of glass fiber fabrics were studied, including vacuum assisted resin transfer molding (VARTM), SEM analysis of interlayer after tests, layer tearing property and data calculation analysis. The experimental results showed that: (1) the tearing strength of the GFRP toughened by short glass fiber increased by 48.13 % than that the GFRP without any toughening treatment, and (2) the damaged samples observed under SEM showed different interface and inter layer morphologies, mechanism of action of five kinds of reinforcement has been analyzed. In this study, the calculation analysis revealed that SGF (20 mm) can make inter layer tearing property enhanced greatly, it is the best in these five kinds of GFRP, GFRP with the reinforcement nap glass fiber fabric has the worst inter layer tearing property of this five.