Abstract: Banko and Yalova-12, varieties of onion were studied for some physical parameters such as size, shape, and density. An instron test machine was used to perform a compression test on both varieties. Modulus of elasticity was found from force-deformation curve(experimental method) and Hertz equation. The effects of the loading direction (polar or equatorial), loading speed, onion varieties, and the calculation methods were examined on the modulus of elasticity. The effects of loading speed and varieties on the modulus of elasticity were found to be significant. Modulus of elasticity was decreased with increasing loading speed. No significant differences were found in values of modulus of elasticity for experimental method and Hertz equation and the loading direction (polar or equatorial load).