In this thesis work analysis of587 gravity data collected in the central patt of the Main EthiopianrnRift (MER), between latitudes 8.00- 8.75N & longitudes 38.75- 39.5E ( consisting of Gedamssarncaldera is made). The data sets incorporate 50 gravity obselvations that are recently collected byrnthe author with his principal advisor & the remaining 537 gravity observations obtained fromrnprevious stllveys carried out by EIGS & Geophysical Obselvatory of AAU.rnThe analysis include compilation in a standard fonnat of the recent & and the previous gravityrndata sets, which require homogenisation to IGSN71 Datum of the data set fi'om the previousrnsUlveys that is found out not available to tIns datum.rnAll available data, about 587 stations, obtained li-Oln the EIGS and partly collected by the author,rnwere reduced to sea level with a Ulnfonn crustal density of2.67 gm/cnl Effects Bouguer massesrnwere calculated applying the simple Bouguer correction. Terrain cOlTection of majority of therndatas was not applied in which case its effect was treated as systematic error in computing thernover all mean square error of the simple Bonguer anomalies at each station. Theoretical gravityrnfield was computed by means of the intematiollal gravity fomlUla of 1967 (GRS67) and tied tornthe IGSN71. The accuracy of the Bouguer anomaly at each station is calcnlated to about Â± 2.8rnmGal. The regional and residual gravity field were calculated from the Bouguer anomaly map byrnmeans of a software that uses Hanning filter.rnThe compiled Bouguer anomaly map shows a strong con'elation between the regional pattemrnand topograplnc feature of the sUlvey area. Owing to Ingher elevations, the adjacent plateaus arernmarked by negative Bouguer anomalies, the minimum of magnitude -245 mGals being locatedrnaround Areb gebya. The maximum gravity values occur in the NE cOlTesponding to the relatively lower elevations. The main Ethiopian rift including Afar is characterised by a relatively positivernanomaly as compared to the plateaus. The high on the rill accounts for the excess Illass at depthrnon which the emst lies relative to the plateaus where a mass deficiency is assumed.rnGravity values on the main Ethiopian rift are generally less as compared to the north pmt of thernEthiopian rift. TIns accounts for the thinning of clusl material towards the Afar along the rift, orrnit can equally be explained as by a thickelnng of a denser material beneath the cl1lst(probably thernanomalous mantle). The margins separating the rift 11'0111 the plateaus are marked by steeprngravity gradients which their magnihlde represent the slope of the escarpment. Steep gradientsrnindicllte the transition of gravity field fi'om the platellus to the rift floor.