A new nonlinear optical crystal, Na3VO2B6O11, hit s been grown by the top-seeded sol Lit ion growl h method using it Na2CO3V2O5 flux. The structure of the compound was determined by single-crystal X-ray diffraction. It crystallizes in the noncentrosymmetric orthorhombic system, space group P2(1)2(1)2(1), with cell parameters a = 7.7359(9) angstrom, h = 10. 1884(12) angstrom, c = 12.5697(15) angstrom, V = 990.7(2) angstrom(3), and Z = 4. Na3VO2B6O11 has, a three-dimensional structure consisting of hexaborate groups connected by VO4 tetrahedra with the sodium atoms distributed in channels through Out the three-dimensional network. The refractive indices have been measured by the minimum deviation technique and fit to the Sellmeier equations. Nonlinearoptical Measurements on the compound demonstrate that the material has second harmonic generation properties, with an efficiency approximately the same as that of KH2BO4.