The experiments were carried out during the agricultural season of 2003 to evaluate two different systems of harvesting soybean crop to choose the most efficient and economic system as well as to determine the optimum operating conditions for both systems. The first system was harvesting soybean crop by combine harvester (Yanmar-CA760) which was tested at four different forward and cylinder speeds under four various levels of grain and straw moisture contents. The second was harvested by hand sickle then threshed, winnowed by Turkish threshing machine that was tested at four feed rates and cylinder speeds under the same above mentioned moisture contents. All experiments were performed at the research farm of RiceMechanizationCenter, Meet El-Deeba, Kafr El-Sheikh Governorate. Results showed that combine harvester (Yanmar-CA760) is strongly recommended since it gave lower losses, damage, costs and higher performance efficiency compared to manual harvesting and gathering followed by mechanical threshing and winnowing using Turkish thresher. The optimum operating conditions for combine harvester (Yanmar-CA760)  are at forward speed of 2.6 km/h, cylinder speed of 10.89 m/s and grain moisture content of 18.50%. However, the optimum operating conditions for manual harvesting and gathering followed by mechanical threshing and winnowing using Turkish thresher was at feed rate of 0.5 kg/s, cylinder speed of 11.99 m/s and grain moisture content of 18.50%.