In this research, the effect of deficit irrigation on some characteristics of five species of medics: physiological properties, yields, plant quality, and resistance to drought in the Islamabad region were investigated. Five different irrigation amounts (0, 25, 50, 75 and 100%) and five species of medics with three replications in a split plot design experiment were considered. The irrigation requirements using Penman-Montith with CROPW AT software on the basis of climatic data of study region with irrigation efficiency of 90% was estimated. The variance analysis indicated that a significant variation at I % level for the effect of medic species on all indices was observed. The results of stress intensity index indicated that minima species had the greatest sensitivity to stress. radiata and turbinata species showed the greatest resistance to drought. Although the rigidula species had the greatest yield in all levels of irrigation it were sensitive to drought. Based on drought tolerance index, rigidula species showed the lowest resistance to drought and had the largest water productivity. Based on the calculated indices rigidula species is recommended for irrigation and turbinata species for rainfed. The orbicularis, and radiata species showed the lower production in rainfed condition.