Abstract-The atomic arrangement and segregation behavior of Ti, Cr, and Y in Σ3 (111) grain boundary of vanadium was performed to illustrate by first-principle calculation. The analyses on the binding energies and geometric positions show that Cr atom is more stable than Ti or Y atom both in the bulk and grain boundary, and Y atom would push away the surrounding V atoms. The computations of segregation energies show that Cr/Y atom segregates at the grain boundary, while Ti atom prefers to stay in bulk V rather than in grain boundary. Furthermore, it is found that Ti/Y atom has a strong driving force to surface segregation. The grain boundary energies calculations and the work of separation and the electron properties show that the segregated Cr can strengthen the grain boundary, whereas segregated Y has the strong tendency to decrease crystallite size.