Abstarct: Drought is one of the climate phenomena of which is repetable annually causes a lots of damages, this phenomenon is one of the main characteristics of all the climates. The effects of drought are not limited to dry areas. One of the areas affected by long –term drought conditions is groundwater resources unfortunately, it is less than the other part. The purpose of this research is to in vestigate drought and its effects on under ground water in a region of Mazandaran. In order to study and study the droughts of the central plains of Mazandaran from the precipitation the rain fall data of Ghaem shahr and Amol station have been used during the 31 year old period (1986-2016) Using the standard rainfall inder inth 3, 6 and 9 month seale drought characteristics are aval uated. The results of this assess ment in di cate that the Ghaen shahr and amol stations have been dying for 5 and 3 years. The most important of these is the 1388 drought is very severe. Also, the drought in the studied area during the statistical period ( 1986-2016) the trend is in crea sing. The relation ship bet ween Spi and ground water was further examined. The results showed that there is adirect relation between SPI and ground water level, and by decreasing the SPI, the ground water Level also decreases but this is a time lag. In studying and analyzing the water balance of piezometric wells align ment and depth maps are plitted on annual, monthly and monthly scale and its all right the piezo 80 cm wells have negative surface area of ( 1986-2016) it has fallen by an average.