Sesame (Sesamum indicum L.) is probably the oldest oilseed known and used by man (Weiss, 1983). Cultivated sesame belongs to the Tubiflorae order, Pedaliaceae family; About thirty-seven species of the sesamum genus have been described, but only Sesamum indicum has been recognized as a cultivated species (Getinet et al. 1998). Although the origin of sesame is still under debate, Mehra (1967) and Mahajan (2007) considered Ethiopia as the place of origin of cultivated sesame. Bedigian (1981) argues that, due to the extensive genetic diversity in East Africa (Ethiopia), it is reasonable to assume that this subcontinent is the primary center of origin and that India would therefore be considered a secondary center for sesame. Sesame seed, also known as sesamum, gingelly, benniseed, sim-sim and til is an important annual oilseed crop. It has been cultivated for centuries, especially in Asia and Africa, for its high edible oil and protein content (Johnson et al., 1979; Weiss, 1983). Sesame is grown between 300 and 1700 meters above sea level, however it grows and produces well at altitudes ranging from 650 to 1250 meters above sea level. For optimal growth, sesame requires warm, frost-free areas, with evenly distributed rainfall from around 300 to 800mm per season is required for reasonable yields. However, optimum yields are achieved in areas with annual rainfall of 500-650 mm well distributed over the 3-4 month growing period. Sesame needs water during the seeding, flowering and grain filling stages. The temperature of 25-37°C favors rapid germination, initial growth and flower formation. A temperature below 20 oC for a certain period of time will inhibit or delay germination, and a temperature below 18 oC after emergence will severely retard the growth of seedlings (Ge...... middle of paper.... .. harvest and increase domestic product growth and domestic product growth by increasing crop productivity Humera type white seeded sesame is prized worldwide for its aroma and sweet flavor and has a premium price. of 100 Ethiopian birr per quintal. Knowledge of the extent and the genetic pattern. The variability present in the sesame population is absolutely essential for further improvement of the crop. Likewise, information on the extent and nature of the interrelationships between the traits they help formulate an efficient multiple trait selection scheme. Furthermore, knowledge of the diversity occurring in a population helps identify different groups of genotypes that can be useful for the breeding program. Therefore this research project was proposed with the following objective To estimate the extent of genetic variability for yield and yield components