Understanding of the effects of historic land use/land cover change helps one to see the impactofthesechangesonstream flow. The main objective of this study was to evaluate the impacts of land cover change in the stream flow of Gumara Catchment in the upper Blue Nile basin. In order to achieve this objective, assessment of the land cover changes from (1973 to 2016) have been evaluated using Land sat image. The three different time satellite images (1973, 1984 &2016)were used. The land cover maps were generated using the Maximum Likelihood Algorithm of Supervised Classification. The accuracy of the classified maps was assessed using Confusion Matrixesand the process produced high accuracy LULC maps for the years of 1973, 1984 and 2016 with an overall accuracyof 82.4%, 87.3% & 90.2% and Kappa coefficient of 80.4, 84 &86respectively. The land use evaluation results showed that the built uparea, water body and cultivated land increased by 3.27%,0.27%,and 30.13% respectively from 1973 to 2016 , slightly decrease in forest and bushby 0.4%, 37.6% respectively andGrass land increased by 8.7% from 1973 to 1984 and decreased by 4.12% from 1984 to 2016. Using two generated land cover maps(1973,1984 and 2016). Generally the analysis indicated that significant increases average flow, wet season flow & volume of peak by 21%, 22% &19.1% respectivelyfrom 1973 to 2016 due to the increment of built up area and cultivated lands.The result indicatesthat Gumara watershed has experienced a significant change in land use and lands cover over the past 43 years and increase surface run off. Asindicates the result it is clear that when land cover is change it affects to climate change, sediment and water quality, river plan form so the future researcher should be focus on the mentioned.