A single crystal of the new noncentrosymmetric material Cs2Ca[B4O5(OH)(4)](2)center dot 8H(2)O has been grown by a slow evaporation method with sizes up to 10 x 10 x 5 mm(3) using an aqueous acetone solution as a solvent. The crystal structure of this compound was determined by single crystal X-ray diffraction. It crystallizes in the Orthorhombic space group P2(1)2(1)2(1) with lattice parameters a = 11.5158(7) angstrom, b = 12.8558(7) angstrom, c = 16.7976(10) angstrom and Z=4. The optical transmittance spectrum was measured on the Cs2Ca[B4O5(OH)(4)](2)center dot 8H(2)O crystal, which exhibits an absorption edge at about 190 nm in the UV region. The powder second-harmonic generation (SHG) measurement indicates that Cs2Ca[B4O5(OH)(4)](2)center dot 8H(2)O is phase-matchable and the signal is about half that of a KDP (KH2PO4) standard. Theoretical calculation shows it has moderate birefringence, and identifies the contribution of cations to the optical properties. (C) 2013 Elsevier B.V. All rights reserved.