Soybean is one of the very important crops in the world that is known for its highest protein content and quality vegetable oil. In Ethiopia, the importance of this crop is increasing tremendously and it is one of the focus crops that are attracting many investors due to its versatile importance. It can be grown over wider agro-ecologies in low to mid altitude areas that have moderate rainfall. Hence, it is exposed to the influence of Genotype x Environment Interaction (GEI). Knowledge of the pattern and magnitude of GEI and stability analysis are important for understanding the response of different genotypes to varying environments and for identification of stable and widely adapted or unstable but specifically adapted genotypes. However, information on the extent and pattern of GEI and performance stability on soybean is generally little. This book provides brief highlights of the concepts of GEI and stability analysis in relation to soybean and discusses the extent and patterns of GEI on grain yield and nutritional qualities of soybean. Moreover, it suggests potential stable varieties that can be used by both small scale farmers and investors.