Abstract: Nitrogen content in aerospace grade vanadium-aluminum（V-Al） alloy has an important influence on properties of the downstream titanium alloy.Nitrogen in V-Al alloy mainly exists as atoms with free state or ions with combination state,and removal for both of nitrogen atoms and ions under vacuum was explored in this paper.Denitrification during the vacuum melting process is mainly realized by nitrogen diffusion to the liquid-gas interface.Furthermore,nitrogen prefers to combine with aluminum in comparison to vanadium,and mechanical vibration can accelerate the elimination of Al N. The product obtained by the proposed method here satisfies the Gf E standards for aerospace grade V-Al alloy.