Detailed examination on growth direction, orientation relationship between two phases and the interface structure were carried out for an alumina/YAG (Yttrium Aluminum Garnet) melt-growth composite (MGC) prepared by the Bridgman method. Transmission electron micrograph revealed that this MGC had in coherent interfaces, and that alumina had a twin. It is suggested that the interface was dominated by the growth of YAG, and that close packed planes of the both phases were well mached, being parallel to the solidification direction.