Single crystals of BaBPO5 with sizes up to 21 x 20 x 18 mm(3) have been successfully grown by the top-seeded solution growth (TSSG) method using Li4P2O7 as the flux. The crystals were characterized by X-ray powder diffraction. The preparation process of starting materials on crystal growth was investigated. The effects of the flux are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.