Abstarct: Estimating recharge is one of the major issues in management of groundwater resources. In this study the recharge quantity into alluvial unconfined aquifer of Aleshter with an area of about 128 km2 was estimated. In this regard, three methods including water table fluctuation (WTF), chloride mass balance (CMB) and water balance were used. Investigating 12-year groundwater hydrograph of Aleshtar aquifer shows a decreasing trend with time. In the current situation, the annual rate of water table decline is about one meter. In order to estimate recharge value using water-table fluctuation method, the value of 0.05 was considered for specific yield baxsed on dominant soil texture in drilling logs and the value of annual recharge into the aquifer was estimated at 28.3 million cubic meters (46% of annual precipitation). Temporal variations of recharge show an increasing trend with time. This is probably related to the increase in capacity of the aquifer to receive recharging water due the decline in water table. The average concentration of chloride ion in groundwater and rainfall were measured at 40.23 and 6.4 mg/l, respectively. Recharge value was calculated about 10 million cubic meters (15% of annual precipitation) using chloride mass balance method. The amount of annual recharge using water balance method was estimated about 22.5 million cubic meters (37% of annual precipitation). Due to the uncertainties in recharge estimation by different methods, rainfall recharge coefficient of 35 to 40 percent was introduced for Aleshter aquifer.