The aims of this study were to evaluation and comparison energy consumption of input and output to potato production by systems of conventional and mechanized farmimg. This research was carried out at arable farmland in East Azarbyjan province in 2006-2007 cropping season. For this purpose, the data were collected from 60 potato farms in East Azarbyjan. Inquiries were conducted in a face-to-face and and grabble statistic, information per Jihad Agriculture Organization of East Azarbyjan province and then used of formula and coefficients special are become equivalent values of used factors and input of this type. The results indicated that total energy inputs in conventional farmimg system (CFS) were found to be 60783.24 MJha-1 (direct energy 44.43%, in direct energy 55.57%, renewable energy 46.96% and non-renewabl 53.03%) and output (production energy) was estimated to be 148268.12 MJ ha-1 and total energy inputs in mechanized farmimg system (MFS) was obtaind 52635.73 MJ ha-1 (direct energy 54.17%, in direct energy 45.83%, renewable energy 39.01% and non-renewabl energy 60.94%) and output (production energy) was 232992.76 MJ ha-1 respectively. The net energy, energy productivity, specific energy value and the ratio of energy outputs to energy inputs was estimated to be 87484.88 MJha-1, 0.58 KgMJ-1, 1.74 MJkg-1 and 2.44, respectively in CFS, and in the MFS was found to be 180357.03 MJ ha-1, 1.04 KgMJ-1, 0.96 MJkg-1 and 4.43 respectively. The results show that the highest share in energy consumption of CFS were: irrigation 24.12%, nitrogen fertilizer 22.36%, seed potato19.72% and also MFS had the biggest share within the total energy inputs includes irrigation 23.21%, nitrogen fertilizer 19.32% and farmer machinery 15.27% respectively. Using the most of energy: Irrigation and nitrogen fertilizer both of the sowing methods can be due to climatic, land topography, society and culture condition of the region.