5 wt% Al and 5 wt% Al-5Ti-1B (ATB) master alloy (grain refiner) were added into pure V to form V-5Al and V-5ATB alloy ingots by arc melting. Optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and microhardness tester were used to analyze the microstructure and hardness variation of V-Al alloy before and after grain refinement. The results show that the grain size of V-5ATB alloy decreases obviously due to the precipitation of long needle-like second phases TiB. Compared with V-5Al alloy, the hardness of V-5TB alloy increases due to strengthening effect of solid solution, fine grain and hard TiB phase.