Field experiments were carried out during seasons 2003 and 2004 at Nuban'a region for harvesting sunflower (Euro-flower) in calcareous soil. Two mechanical harvesting methods (mower then thresher) and combine harvester were compared with traditional method (manual then thresher). The mechanical harvesting methods were done at five different field speeds 2.5, 3.1. 3.6 4.0 and 4.5 krrtih for mower and combine. Three different drum speeds (450. 500 and 550 rpm) were also effected on grain losses and damaged grain for combine and thresher machines at three different moisture contents 878, 10.68 and 13.37 %. Field capacity. Fuel consumption, power and energy requirements were calculated. The experimentai results showed that the highest losses for mower and combine header were 4.19 % and 3.03 % respectively at forward speed 4.5 kmfh and moisture content 878 % besides sickle loss was 3.59% at the same moisture content. Increasing thresher drum speed from 450 to 550 rpm increase threshing losses about 0.46 % and damaged grain by 1.35 % at feed rate of 1 Mgih. Total combine grain lessee was 7.27 % at field speed 2.5 km/h, drum speed 450 rpm and moisture content 8.78 % (including grain damaged). The actual field capacity was low under sickle (one labor can harvest 0.025 fedlh) and mower. Actual fieid capacity increased about 2.8 times with combine than mower under the whole fonvard speeds. Combine consumed the lowest energy 33.96 ktfed compared with mechanical method 57.24 kWh/fed at field speed 4.5 kmrh and traditional methods. 34.62 kWhifed (at thresher drum speed 550 rpm). The highest criterion cost with manual is 113.03 LEifed at grain moisture content 8.78 %. in the mean time; the highest criterion cost with mower is 94.39 LE/fed at field speed 4.5 kmfh‘ and grain moisture content 8.78 %. The highest criterion cost with thresher is 175.10 LElfed at drum speed 550 rpm and grain moisture content 8.78 %. The highest criterion cost with combine harvester is 202.96 LErfed at field speed 4.5 km/h: drum speed 550 rpm and grain moisture content 8.78 %.