The study was aimed to evaluate the adaptability and stability of the soybean genotypes based on the seed yield and the other observed characteristics in the sites cultivated second crop soybean of Turkey which have Mediterranean climate conditions using the GGE biplot analysis method. The experiments were performed under irrigated conditions in 2014, 2015 and 2016 in four different locations (Adana, Antalya, Izmir and Sanliurfa) of Turkey. Fourteen soybean genotypes consisting of 10 advanced soybean lines and four standard varieties were analyzed by a randomized complete block design with 4 replications. The combined analysis of variance revealed significant (P<0.01) effects for all sources of variation (environment, genotype, and GxE interaction) for the seed yield and yield components. Genotype and environment accounted for about 2.59% and 51.04% of the total variation for seed yield, respectively, while the GE interaction explained 20.84% of the total variation. According to the GGE principle, five mega-environments were formed in the present study. Results of the research revealed that genotypes G8 (KANA), G9 (KASM 02), G11 (ARISOY), G3 (BATEM 306), G1 (BATEM 207) and G12 (ATAEM 7) were found as stable. According to GGE Biplot analysis for all traits and genotypes, G4 (BATEM 317) had the largest values for plant height, first pod height, days to 50% flowering, days to maturity and seed yield.