High-quality K 2 Al 2 B 2 O 7 (KAB) crystal with a dimension of (15x12x4mm 3 ) was grown by a modified middle-seeded solution growth method. This result allowed us to characterize nonlinear optical (NLO) properties of KAB for the generation of UV light. From our result, KAB possesses moderate birefringence for UV light generation, a significant effective NLO coefficient and is chemically as well as physically stable for practical applications.