In this paper, we report with regard to the growth of potassium tantalate niobate (KTaxNb1-xO3:KTN) single crystals with compositional uniformity by the vertical Bridgman (VB) technique. First, relationship between the primary phases at the initial solidification region in KTN boules was investigated by directional solidification from melts with various compositions. Second, KTN crystals were grown by the normal VB technique using a [100]-oriented KTaO3 seed from K-rich melts. KTN single crystals were obtained above the KTaO3 seed. But, the proportions of Ta and Nb in the grown crystal gradually changed with the progress of growth, the tendency of the composition to change qualitatively obeys the binary phase diagram of KTaO3－KNbO3. Finally, based on results of the directional solidification and the normal VB crystal growth, KTN crystals with compositional uniformity were grown by the modified VB technique with the special continuous supplying system.
