The enrichment of vanadium and crystallization and growth of V-concentrating phase in V-bearing steelmaking slag are studied by adding SiO₂ and Al₂O₃ with the method of melting-cooling. The results show that when15% SiO₂ and 20% Al₂O₃ are added in slag, respectively, vanadium can be enriched in solid solution of Ca₃[(V,P,Si)]O₄]₂ from the original phases of 2CaO·SiO₂(C₂S) and 2CaO·Fe₂O₃(C₂F). The contents of V₂O₅ in Ca₃[(V,P,Si)]O₄]₂ reach 24.38% and 14.90%, respectively. It is demonstrated that when the slag is added by Al₂O₃, V-concentrating phase can nucleates homogeneously at1325℃and heterogeneously at 1350℃. When holding at crystallization temperature of 1300℃, the crystals of V-concentrating phase grow from mean diameter of 6.28μm for 5min to 25.19μm for 580 min, and the number of crystals per unit area is decreasing.