T The research area administratively is located in Mount Kukusan and surrounding area, Kokap District, Kulon Progo Regency, Special Region of Yogyakarta Province. Geographically, the study area is located at coordinates 110° 03’ 56,8” - 110° 05’ 34,5” East Longitude and 07° 49’ 15,6” - 07° 51’ 05,8” South Latitude, with an area of ± 9 km² (3km x 3km). In physiographic, the research area isincluded in the Kulon Progo Mountains physiographic, where the indications ofalteration and metal mineralization are found. The rocks in the research area consists of 2 (two) lithologies , those are andesite unit (shallow intrusion and lava) that have aged Early Miocene or who have an absolute age range from 29.63 - 22.64 million years ago, and also microdiorite intrusion unit that have aged Late Miocene or who have a absolute age range of 8.10 ± 1.19 million years ago. Igneous rock was then going to be the heat source and hostrock of hydrothermal processes in the research area. Based on the analysis of altered rock thin section and XRD analysis, present three alteration zones in the research area, those are alteration zone of quartz-sericitechlorite- carbonate, alteration zone of quartz-chlorite-carbonate-epidote, and alteration zone of quartz-chlorite-carbonate-clay. Further, referring to the proportionality by Corbett and Leach (1997), the alteration zones be compared become phyllic alteration zone, propylitic alteration zone, and subpropylitic alteration zone. The process of alteration in the research area was divided into two, those are the process of replacement and filling. Interpreted that subpropylitic alteration stages is present the very latest, overprinting and cutting other alteration zones. The order of geological structure in the research area occurs at a younger stage of Late Miocene epoch. This tectonic activity produces joint and fault structure. In the research area, the joints structure those are formed are shear joint form, andalso extension joint form dominant filled by veins. Meanwhile, the faults structure those are formed are Papak dextral fault and Mount Kukusan normal right slip fault. Mineralization in the research area included into the epithermal low sulphidation environment. In addition, the mesothermal environment is interpreted little recorded too before the presence of low sulphidation epithermal environment. Based on field observations and mineragraphy analysis, the presence of ore mineralization are pyrite, sphalerite, galena, chalcopyrite, and electrum. Meanwhile, based on AAS (Atomic Absorption Spectrofotometry) analysis, metal ore mineralization potentially from high to low is Zn (zinc), Pb (lead), Cu (copper), Ag (silver), and Au (gold).