The Gharib area is sited between latitudes 28º 10' 12" - 28º 01' 37" N and Longitudes 32º 55' 02" - 32º 38' 29" E, in the Eastern Desert- Egypt, covers an area 500 Km2, this area is covered mainly by younger granites; The younger granite is considered as one of the most important basement rock due to its economic value, where it used in different purposes metallic purpose, and as raw material which are used for ornamental stones. Remote sensing is an important and useful tool for mapping and detection of alteration zones, which properly important for identifying ore deposits. ASTER imagery are reliable, accurate and of good ability to assist geologists in mineral exploration stages. Using image processing technique such as band rationing method (bands ratio 4/8, 4/2 and 8/9 used for hydrothermal alteration zones to detect gold occurrence, band ratios 4/5, 4/6 and 4/7 in RGB Show the discrimination of hydrothermal alteration and band ratios 5/7, 3/1 and 4/3 show the iron gossan an iron- bearing sulphide ore bodies where gold are enriched in this oxidation zone area). The hydrothermal alteration zones are detected in the South western side of the study area Gabel Gharib which located in the northern part in the Pan African Belt, and by using Classification methods such as SAM and MLC are used to make an up-to-date geologic map with scale 1:50,000. These methods Results in detecting gold mineralization in the study are also verified that the methods are fruitful and could be applicable elsewhere.