Droughts are the most destructive weather events which caused considerable damage to the natural resource sector as well as in human life. Minab river basin was selected because of Esteghlal dam and importance of groundwater and surface water resources and the plain located in this basin. The frequency of droughts was determined using RDI and SPI in rain gauge stations located in the study area. The results showed that both SPI and RDI index for mild and moderate drought frequency region were fitted. SPI based on the effective theory, showed better adaptability with the study area. Therefore the index was selected to assessment drought and water resources relationships. Then in order to evaluate the effect of drought on surface water resources the relationship between the annual mean changes discharge in hydrometric stations near the plain. The results showed that this relationship is statistically significant correlation. In the next step the effects of drought on groundwater resources were calculated by using the bivariate correlation, coefficient harvest and drought effects on groundwater level changes and were found to fall in the water level of all plains were affected by the drought, with high impact factor, except plain Mosaferabad because wells located on the second table and major portion of aquifer recharge it through hard formations highlands done and plain rain is less affected.