Evaluation of farm irrigation system plays a fundamental role in improving surface irrigation and in providing information used to advice irrigators how to improve their system operation. Furrow irrigation is one of the common methods of applying water to crop in Kobo –Girana irrigation project. Water use and hydraulic performance parameters evaluation with furrow irrigation systems tend to be low. Hence, the main objective of this study was to evaluate the existing hydraulic performance parameters, to optimize furrow irrigation and to determine the optimal design variables of furrow irrigation at the study area. In this study, field measurements (furrow geometry, infiltration rate, inflow rate and soil properties) were conducted and used as a primary data. The field measurements were carried out on four existing furrows in the study area. The collected data that used as input parameters were analyzed by using SIRMOD and WinSRFR software models. These software’s models were analyzed from field tests conducted on 3m wide and 45 m long furrow with slope of 0.2% and inflow rate of 2 l/s. These slope and inflow rate with required depth was not suited on furrow short length of 45 m under blocked end boundary condition. These measured input parameters resulted in low application efficiency of 47.65 and 47 % and high deep percolation loss 52.35 and 53 % for SIRMOD and WinSRFR software respectively. So, in order to optimize the hydraulic performance of furrow irrigation, the optimum furrow length of (45m, 65m and 100m) and 3m width were selected to realize the efficiency and uniformity with inflow rates of 6 l/s and 10 l/s at furrow bed slope of 0.1%. Based on those selected input parameters the optimal output value of application efficiency for furrow length of (45m, 65m and 100m) were 92%, 90% and 86 % respectively simulated by WinSRFR ; Similarly the simulation value of application efficiency by SIRMOD model were 93.44%, 91.74% and 86.85; distribution uniformity simulated by WinSRFR were 82%, 92% and 82% and SIRMOD simulated values were 94.45%, 91.47% and 85.54%; deep percolation simulated value 9 %, 10% and 15% by WinSRFR and 5.5%,7.37% and 12.18 % using SIRMOD model. Hence, when the irrigators begin to implement furrow irrigation it is good to use optimal design variables (inflow rate, furrow length, cutoff time and furrow bed slope) to consider management of irrigation water save and improve hydraulic performance parameters. Based on the recommendation the two models give good result and can be used both software models for evaluation and design of furrow irrigation. Key words: Furrow irrigation; design variables; optimal Performance; WinSRFR; SIRMOD.