A laboratory oil extraction line was designed and fabricated to determine the operational parameters affecting crushing and oil extracting of different olive varieties grown in Arish, Sahrawy (Cairo-Alexandria road) and Siwa areas. For crushing experiments, three different hammers shapes (flat, triangular and wing), three different screen holes diameters (4, 5 and 6 mm) and four different hammer speeds (1500, 2000, 2500, and 3000 rpm) were examined to determine the percentage of partides diameters of the olive paste at the range of 2.25-4 mm as an optimum size for oil extraction from olive paste. Hydraulic press extraction of oil for different crushed samples was also conducted at a pressure of 85 bar and remaining time of 60 minutes to determine the relationship between the percentage of particle diameters at the range of 2.25­4 mm and the percentage of remaining oil in the olive paste. The results show that for all studied varieties, the highest percentage of olive paste particles diameters at the range of 2.25-4 mm was obtained for the triangular hammer shape at hammer speed ranged from 2000 to 2500 for the varieties of Sahrawy area. At the same time, the proper screen holes diameter ranged from 4 to 5 mm. The oil extraction experiments showed that for all studied varieties, the lowest percentages of remaining oil in the olive pastes were obtained for the samples of particle diameters at the range of 2.25-