This research was carried out in order to determine the effect of deficit irrigation on physiological and biochemical characteristics of six commercial olive cultivars Mission, Konservolia, Amphisis, Zard, Roughani and Shengeh in field conditions in 2014. The layout was as a factorial experiment in a complete randomized design with three replication and two factors, including olive cultivars and irrigation reginaes. Irrigation treatments were full irrigation, continuous deficit irrigation (irrigation based on 60 percent of full irrigation) and regulated deficit irrigation (irrigation based on 60 percent of full irrigation plus no irrigation during pit hardening and fruit verasion). Some physiological and biochemical traits including relative water content (RWC), ionic leakage, calcium, potassium, chlorophyll a, chlorophyll b, total chlorophyll, proline content, total soluble sugars, phenol and malondialdehyde contents were measured. The results showed that full irrigation treatment increaed RWC, Ca, K, chlorophyll a and total chlorophyll in olive cultivars. No significant differences were observed in chlorophyll b among different irrigation treatments. Continuous deficit irrigation and regulated deficit irrigation were in  the same statistic class in many critical traits including RWC, Ca, K, chlorophyll a, total chlorophyll, proline content, total soluble sugars, phenol and malondialdehyde contents. According to the ‘Shengeh’ and ‘Konservalia’, were more tolerance to water stress the olive cultivars highest (RWC), K, chlorophyll and the lowest malondialdehyde content, than other studied cultivars.