In order to investigate the effect of partial root zone drying on yield and some physiological characteristics of two potato cultivars, this experiment was performed as split- split plots based on randomized complete blocks design with three replications in Chahar Mahal va Bakhtiari farm Research Center of Agriculture and Natural Resources in 2013-14. The tested treatments in this research included two irrigation methods furrow and tape drip irrigation at the main plots, two potato cultivars included Almera and Burren in  sub plots and four deficit irrigation treatments at four levels of irrigation at the amount of 100, 80 and 65 percent  of soil allowed moisture depletion and incomplete root irrigation (PRD) as the sub-sub plots. The results showed that Burren cultivar in comparison with Almera cultivar in all the deficit irrigation treatments had superiority regarding to  tuber yield, water productivity and drought tolerance as Buren cultivar compared with Almera cultivar caused increasing in total tuber yield and water productivity by 19 percent. Effect of deficit irrigation on tuber yield, water efficiency, starch percentage, soluble sugar content, amount of proline and plant chlorophyll was significant at one percent probability. The highest amount of tuber yield equals to 59/02 tons per hectare due to to the Bourne cultivar and full irrigation was obtained. Most water efficiency equals to 13/20 kilograms per cubic meter was obtained related to Bourne cultivar and PRD treatment. Therefore, due to resource constraints for efficient use of water, Bourne cultivar as a cultivar with high quality and quantity yield, and deficit irrigation PRD was recommended as a way to conserve water.