The phase equilibrium and the crystallization process of lead iodide (PbI2) melt have been primarily investigated according to the lead-iodine phase diagram. It is found that the iodine evaporation and the segregated lead deposition are the two important factors that affect the PbI2 crystal quality. The new method of Pulling U-type quartz growth ampoule has been made to impede the decomposition of PbI2 and the vaporization and condensation of iodine. An orange and translucent PbI2 single crystal of large size was obtained by the improved growth method, i.e. U-type ampoule pulling. Resistivity of the as-grown crystal is up to 4 x 10(11) Omega cm, and IR transmission is up to 45% in the region from 7800 to 450 cm(-1). Therefore, the improved growth method is a promising convenient new method for the growth of high quality Pbl, crystals. (c) 2006 Elsevier B.V. All rights reserved.