Different Studies show that power distribution systems in Ethiopia is the weakest arearncompared to generation and transmission. In this thesis work, Geographic Information rnSystems (GIS) based modeling and performance improvement of Adama town 15kVrndistribution network was done that can enable operation and planning offices to take rnmeasurements based on the proposed methods. rnThe attribute and electrical data are obtained from the already available data base andrnalso additional data was collected on field visit. Then database was created and the rnnetwork was mapped using Geographic Information Systems (GIS). By integrating thernGIS database with the Electrical Transient Analyzer Program (ETAP), modeling and rnpower flow analysis were done by ETAP Software for all ten (10) 15kV feeders under thernstudy. Line 1 was selected as it is experienced significance power loss and voltage droprncompare to the others. This thesis was mainly concerned with the power losses andrnvoltage drop of the distribution network. Optimal Capacitor Placement (OCP), Conductor rnUpgrading (CU), and the combined solution of OCP and CU techniques were used tornreduce power loss and improve voltage profile for both the normal and design scenarios rnfor distribution network. rnThe result shows that the combined solution of OCP and CU gives the maximum activernpower loss reduction (57.6%), followed by CU (42.9%) and OCP (32. 9%). It also shows rnthe highest bus voltage prof ile (≥ 0.971pu), f ollowed by OCP (≥ 0.942pu) and CU (≥rn0.91pu). However, the combined solution of OCP and CU needs higher initial capitalrninvestment cost of Birr 8,652,573.61 with return of investment of 1.40 years, whereas CU rnand OCP needs initial capital investment cost of Birr 5,607,309.85 and Birr 3,045,263.76rnwith return of investment of 1.21 year and 0.86 year, respectively. Thus, among the threerncases, OCP is selected f or the current scenario due to its best active power lossrnminimization and minimum voltage drop with best return of investment. On the other rnhand, the result for the design scenario (10 years forecast) shows that the combinedrnsolution of OCP and CU gives the highest active power loss reduction (57.7%), followedrnby CU (46.3%) and OCP (22.3%). It also shows the highest bus voltage profile (≥rn0.894pu), while the maximum bus voltage for CU and OCP were 0.840pu and 0.835pu, rnrespectively. Hence, among the three cases, the combined solution of OCP and CU isrnselected for the design scenario (10 years load forecast) due to its best power loss rnminimization and minimum voltage drop. rnIn general, the results of this study revealed that for short term solution, optimal capacitor rnplacement (OCP) method is proposed, whereas for long term solution, the combinedrnsolution of optimal capacitor placement and replacement of overloaded conductor with rnoptimal conductor size is proposed, to be implemented to improve the performance ofrndistribution network on the bases of loss reduction and voltage profile improvement.