The agricultural sector of every country is vulnerable to drought and the consequences of climate change; Therefore, planning to monitor and manage agricultural drought can help to control the damage caused by drought. The use of satellite images is used as a useful tool to monitor agricultural drought.Therefore, in this research, TCI, VCI, and VHI remote sensing indices have been investigated in seasonal, 6 month, and annual scales, and the correlation coefficient with SPI standardized precipitation index has been investigated using the data of 4 rain gauge stations in Urmia Plain during the period of 2003 to 2018.The results show that the distance measurement indices on an annual scale have a higher correlation compared to the seasonal and 6 month ones with the SPI index, and in general, the correlation coefficient of the VCI index on an annual scale is higher than the TCI and VHI indices. By dividing the Urmia plain into 17 study areas through the Thyssen polygon method, using piezometric wells in the Urmia plain to investigate remote sensing indicators on a smaller scale, it shows that in each region, depending on the specific climatic conditions and vegetation, there is a different correlation coefficient with the remote sensing indicators. and it is not possible to choose an optimal index for the whole region of Urmia; Therefore, to choose the optimal drought index, it is suggested to consider the scale of the studied area to be smaller in order to choose the best index for agricultural drought monitoring.