A chelating reagent sulfosalicylic acid (SSA) as a new additive was added into the KDP solutions in a small amount (1 wt%) and metastable zone widths were measured for different saturation temperatures when compared to the pure system. Potassium dihydrogen orthophosphate crystals were rapidly grown from both pure and SSA-added solutions by adopting the same crystal growth procedure. The crystal grown from SSA-added solution was subjected to optical transmission and laser damage threshold studies as compared with the crystal grown by traditional growing method. (C) 2004 Elsevier B.V. All rights reserved.