Abstract: The key factors on the fiber volume fraction and thickness uniformity of the composite molded via vacuum assisted resin infusion(VARI) technology were analyzed, i.e. resin flow control, state of preform, state of fabric and viscosity of resin. The effects of the key factors on the thickness and the fiber volume fraction of the composite molded via VARI technology were verified individually by process test. The results of the tests show that the fiber volume fraction and thickness uniformity of the fiber reinforced resin composite laminates are comparable with those of the composite article molded via prepreg/autoclave process, wherein the fiber reinforced resin composite laminates were molded by HFVI (high fiber-volume vacuum infusion) process and BA9914 resin and vacuum treated U3160 unidirectional woven fabrics are used.