This study was carried out to investigate of the performance for Sweet potato Harvester using Power-tiller. There was highly reduction in energy consumption using by Sweet potato Harvester of Power-tiller. A diesel engine with four cycle with single cylinder, water cooling and rated output 8.1 kW/2200 rpm was selected. The experimental factors for performance test, engine speed ranged from 1000 rpm to 2400 rpm, and BSFC, efficiency, traction power, and vibration were measured. The results obtained were as follows; engine output were increased from 4.4 kW to 5.74 kW at 1800 rpm and increased to 8.83 kW at 2400 rpm The specific fuel consumption was decreased to 320 g/kW.h at engine speed 2200 rpm and the traction power were showed 420~440 kgf.