Y123 and Y211 powders were synthesized by solid-state reaction method. YBCO superconductor specimens were prepared by unidirectional solidification technique. The microstructure and the structural characteristics were observed by means of the optical microscope, X-ray diffraction (XRD), scanning electron microscope (SEM). The results showed that the specimen have a highly aligned structure, it was observed obvious laminated structure of Y123 crystal. Crystal growth mechanism of YBCO was investigated. Jackson's factor of Y123 crystal was calculated. Interface form was judged tentatively theoretically. The specimen was rapidly quenched by quick pulling. Solid/liquid interface structure was observed. It was concluded that a-b plane was faceted grow forms and layer growing along c-axial on a-b plane.