Single crystal of the semiorganic NLO material NaB(L-C4H4O5)(2) has been grown with sizes up to 8 x 5 x 2 mm(3) by the slow evaporation method. The crystal structure of this compound was determined by single crystal X-ray diffraction. It crystallizes in the Monoclinic space group P2 with lattice parameters a = 5.4045(11) angstrom, b = 11.692(2) angstrom, c = 9.4773(19) angstrom and Z=2. Thermal analysis demonstrated NaB(L-C4H4O5)(2) are thermally stable up to 280 degrees C. NaB(L-C4H4O5)(2) exhibits an absorption edge about 220 nm in the UV region. The powder second-harmonic generation (SHG) measurement performed on the ground crystal indicates that it has a NLO efficiency of about 2 times that of KDP (KH2PO4) standard. In addition, the origin of stronger SHG effect was discussed. (C) 2013 Elsevier Ltd. All rights reserved.