The purpose of this study was carried out by oberserving to composition of an oxide on the surface of Dental porcelain alloy according to the conditions of its heat treatment and analysing the change composition on its surface. Morphological change of the heat treated dental porcelain alloy have been investigated with SEM and EDX. The result of this study is summarized ad follows. The surface indium concentration of specimens increased as the heat treatment temperature and the oxygen partial pressure increased.