Madden and Julian (MJO),, a large-scale climate signals,, is one of the factors that affect regional meteorological events in the tropical and even the subtropical areas. The effect of MJO on precipitation occurrence has generally been investigated in the southern parts of Iran. The purpose of this study is to investigate the spatial distribution of probability of precipitation occurrence (PPO) in Iran based on MJO phases. The data used are the daily MJO index and precipitation from the ERA-Interim reanalysis data that covers Iran’s region in cold months of the year (November to April 1979-2016). The negative and positive phases of the MJO, (i.e. MJO- and MJO+) are based on the Wheeler and Hendon (2004) index. The analysis of coincidence of probability of precipitation occurrence (PPO) and Madden and Julian phases showed that the PPO in Iran in the negative phase of MJO- decreases as a nearly regular from the south to the north of the country and indicates reduction of the effect of MJO on precipitation event. All grid points received at least 45 percent of their precipitation during the negative phase of MJO. The PPO is about 75 percent in the south of Iran. On the contrary, the PPO in the positive phase of MJO, increases as a nearly regular from the south to the north, and all grid points receive at least 25 percent of their precipitation in coincidence with positive phase of MJO. Maximum value of PPO in the north, and especially in the northwest of Iran, is about 60 percent which has increased almost 20 percent compared to MJO-. The lowest PPO coincidence with the negative phase of MJO is related to the southernparts of Iran, near 25° N latitudes, where the PPO decreases about 50 percent in comparison to the negative phase of MJO.