Abstract: One of the key questions attracted attention in the resource exploring field is the potential from an intrusion to produce metals. Hence determining the macroscopic indicators of ore-bearing intrusion and providing its theoretical interpretations are of the important responsibilities of scientific studies. However, due to the traditional petrology is mainly concerned with formation and evolution of the dry or H2O-unsaturated systems, but generation of the endogenic mineral deposits is mainly relative to the fluids, the obtained progresses in petrology often can not satisfy exploration geologists. This paper, based on the theory of metallogenesis by transmagmatic fluids, aims at analyzing the features of melt-fluid interaction and their potential effects on ore-forming processes. It is suggested that the rock-forming processes involving huge fluid are obviously different to the generally recognized magmatic processes, and they should leave distinct petrographic signals. Adding or reducing fluid induces density and viscosity of the magma to be changed obviously and modify the solidus temperature and liquidus phase relation and the eutectic composition. Therefore, the textures and structures of intrusive rocks reflect the degree of fluids involved in the rock-forming processes, and can be used as indicators for ore-forming potentials of an intrusion. Separation of the fluids from a melt increases the melt viscosity up to orders of magnitude and solidus temperature and induces to rapid consolidation. Subsequently, portions of the metal-bearing fluids must be trapped into and between the crystal grains, and eutectic and /or poikilitic texture and disseminated structure should be formed. These texture and structure, therefore, indicate which intrusion is the conduit for the ore-bearing fluids. The rheology of poly-crystal magma and the poly-phenocryst porphyritic texture, which broadly occur in many orthomagmatic ore deposits, are of irreconcilable contradicting features in terms of linear system. However, it can be attributed to the unexpected fluxing of the ore-bearing fluid flow into the barren magma. Accordingly, the poly-phenocryst porphyritic texture is a reliable indicator showing preservation of the most of ore-forming metals in the magma body without significant escape. In addition, several other supplementary indicators, which can be used to integratively evaluate the ore-producing potential of an intrusion, are suggested in this contribution. Finally, the authors have concluded that the ore-forming processes involving huge fluids are non-linear and produce series of specific fabrics with important signification for evaluation of mineralization.