We prepared superconducting Bi2Sr2CaCu2Ox, glass-ceramics by the melt-quenching method (glass-ceramic route) and examined the effect of annealing condition on their microstructures. In the sample annealed at 820°C for 24h (one step), the surface (<500 u m) had a homogeneous structure, but the large grain growth and the porous structure were observed in the inside of sample. In the sample annealed first at 700°C for 24h and then at 820°C 24h (two step), the homogeneous and dense structure without any pore was observed. The relation between the difference of microstructures and the formation mechanism of superconducting crystals was clarified. It was found that a liquid phase was created in the inside of bulk during the continuous heating to around 800°C and a rapid grain growth of superconducting crystals in the inside was due to the formation of this liquid phase.