Nine soybean varieties representing most of known maturity groups were evaluated at four planting dates i.e 1-t. 15th, May, 1and 151!i_June. Seed yield data were subjected to phenotypic stability analysis according to the procedure proposed by Eberhart and Russell (1966). The results revealed that the two varieties (Williams 82 and Clark) were more stable than the Crawford and Columbus under the environments study. The unstable varieties i.e. (Crawford and Columbus) seemed to have high seed yields above grand mean. These varieties, however, could be over looked because their high potential was limited to particular environments. Crawford and Columbus varieties gave the highest yield when sowing in 15th May.