Unidirectional solidification processing, including Floating Zone Melting, Vertical Bridgman, and Laser Zone Melting methods for making high Tc superconducting oxides has been investigated. The effects of processing parameters, growth rate (R) and temperature gradient (G), on texture, morphology, and structures of unidirectionally grown crystals were investigated. Two different crystallization mechanisms were recognized, one is non‐equilibrium phase transformation under high GR conditions, and the other is due to local equilibrium phase transformation under low GR conditions. Strongly aligned structures were obtained at high G/R ratios with low GR value. The interrelation between the superconducting characteristics and textured structure produced were also discussed.