The agricultural sector remains the main source of livelihoods for rural communities in Ethiopia. However, the climate which has remained relatively static for years has now become very dynamic and unpredictable and has brought worst effects on the agriculture sector by affecting the two most important direct agricultural inputs, precipitation and temperature. Therefore, this study investigated the trend of climate change, adaptation strategies they used, and factors that influence the choice of their adaptation decisions over koga watershed by sampling 140 farm households. Both primary and secondary data were used for the study, and Mann Kendall test and Sen’s Slope estimator were used to analyzed the trend & magnitude of climate change while descriptive statistics and multinomial logit model were employed to analyze adaptation strategies, they used and determinant factors that influence the choice of adaptation strategies respectively. The result indicated nonsignificantly increasing trend in annual and summer rainfall with decadal increment of 24.4mm and 40.0mm respectively. Whereas maximum and mean temperature for the last 30 years (1987-2016) shows statistically significant increasing trend with recorded increment value of 1.5oc and 1.2oc respectively. The local farmers perception results agreed with the climate data analysis. They used crop variety, crop diversification & chemicals, soil and water conservation, tree planting and supportive irrigation to adapt the climate change & variability effects in the watershed. Farmers’ capacity to choose effective adaptation options in the study area significantly influenced by age, land holding, farming experience, livestock ownership, education, soil fertility, market distance, availability of capital, access to extension and farmer to farmer extension service. Improved technologies and short duration high yielding crops which are economically efficient, environmentally sound or suitable and easily accessible should be developed through research and efforts should be made to make the seed available to farmers. In general, interventions that enhance income, access to credit, access to farm inputs, extension services, access to market and infrastructure development should be an integral part of climate change adaptation policies and strategies. Keywords: climate change, adaptation strategies, Mann Kendall test and Sen’s Slope estimator and Multinomial logit model.