The morphology of melt (and fluid) in intergranular pores of rock under high-temperature and high-pressure is one of forward branches in modern petrology. In this branch, the morphological features of melt (and fluid) in intergranular pores of rock, interconnectivity, and the relation between melt (or fluid) and mineral crystals around them under high-temperature and high-pressure are studied. Some observational methods of materials science are  used in the study of this brach. The interfacial energy theory of physical chemistry is theoretical basis of this branch. The studies of morphology of melt (and fluid) in intergranular pores of mantle rock under high-temperature and high-pressure are very important for partial melting of mantle, asthenosphere, and metasomatism of mantle. In this paper, the theoretical basis, experimental method, and some results of this branch are reviewed.