studies of interactively enhanced Landsat thematicrnmapper (TM) imagery integrated with field survey and aerialphotorninterpretations were carried out to map the lithologyrnand structures of the study area located in the axial zone ofrnthe Main Ethiopian Rift. The Ethiopian Rift has been studiedrnfor decades using a variety of geological and geophysicalrntechniques, but synoptic mapping of the lithology andrnstructures and analysis of regional structural relationshipsrnhave not been previously studied applying high resolutionrnsatellite digital data. By combining Landsat TM data withrnresults from conventional method of geological mapping fourrnmajor serieses of volcanic rocks have been identified,rnnamely: 1. A lower series of pyroclastic deposits dominatedrnby greyish green ignimbrite (Wedecha series), 2. A basaltrnseries of transitional to subalkaline basalts characterrn(Anole Series), 3. pyroclastic deposits of the Rift floorrndominated by pumice and ash falls (Bora Series) and 4. Recentrnlava flows extruded through Wonji Fault Belt openings (JanornSeries). In addition, four sets of structures were mapped: 1.rnMain marginal NE-SW striking normal faults, 2. E-W to NW-SErnstriking strike slip faults that have dextrally displaced thernmarginal faults, 3. NNW-SSE striking cross-rift lineamentsrnand 4. the youngest and active NNE-SSW to N-S striking faultsrn(Wonji Fault Belt). Using different techniques of enhancementrnmost lithologic contacts and lineaments that had not beenrnindicated in any existing geological and structural maps forrnthe region were carefully mapped with better accuracy,rnminimum expense and shorter sorter field season. It has beenrnobserved that tectonism preceeds volcanism in time and therntype of volcanic rocks assemblage and composition reflectsrnthe degree of rifting and intensity of tectonism that hadrninitiated the volcanism.