Drought has been perpetually noteworthy for researchers due to its significant consequences. Study of Drought trend and its relation with the other atmospheric phenomena, and consequently, drought prediction using indices play a key role in water resources planning and management. This research has been studied the relationship between ocean oscillation indices NAO and SOI and such drought indices as RDI and SPI in Iran. In this regard, based on whether the data series follows normal distribution or not, correlation between these indices has been tested using non parametric test Pearson and Spearman. Results indicate RDI and NAO in Babolsar, Bandarabbas, Birjand, and Khoramabad are correlated. In addition, the hypothesis of existing correlation relationship between RDI and SOI of Bam, Bandarabbas, Birjand, Orumiye, Shahroud, Mashhad, Sabzevar, Shahrekord, and Tehran is significant. SPI and NAO in Babolsar and Rasht are correlated. Veracity of hypothesis of correlation relationship between SPI and SOI in Shahroud, Mashhad, Sabzevar, Shahrekord, and Tehran were confirmed. Generally, stations located the north of the country show the highest correlation coefficient due to various plausible reasons such as neighborhood to Caspian Sea and consequently, effect of ocean oscillation on precipitation pattern and drought. In contrast, at southern part of the country except Bandarabbas, despite of their closeness to Persian Gulf show no correlation between the indices. This can verify this hypothesis that drought pattern in this region may be correlated with other ocean oscillation indices. All in All, none of the correlation coefficient between the indices was considerable. The highest one observed in Tehran Station and it was equal to -0.154 between RDI and SOI. Thereupon, developing a model to predict drought using these indices is not suggested.
