Abstarct: Azna plain having 104 km2 area, is one of the important plains of Lorestan province that receives the groundwater outputs of Aligoodarz and Momen-abad plains from the east and the northwest, respectively. The main purpose of this research is investigating the hydrogeological and hydrogeochemical properties of Azna plain as well as quantitative and qualitative impacts of the groundwater flow entering from Aligoodarz and Momen-abad plains on this plain. To do that, Azna plain and the mentioned inputs were evaluated from quantity and quality point of view. Unit hydrograph showed that the groundwater levels in plains of Azna, Aligoodarz and Momen-abad have dropped about 0.88, 0.74 and 1.61 meters per year. According to the amounts of drop in groundwater level and specific yield, deficit contents of reservoir for Azna, Aligoodarz and Momen-abad plains are approximately 3.6, 0.9 and 4.4 million m3, respectively. baxsed on the prepared Iso-potential map, Discharge amounts entering into Azna plain directed from Aligoodarz and Momen-abad are about 5.8 and 0.27 million m3 per year, respectively. Thus, it can be concluded that the entering groundwater volume directed from Aligoodarz plain is relatively considerable while the entering groundwater amount directed from Momen-abad is negligible. For hydrogeochemical investigation of exsiting wells in the area, sampling was conducted in June, 2015, and after analyzing samples, it was found that the groundwater type in Azna plain and the mentioned entrances is calcic bicarbonate. baxsed on Piper diagram, weak acids and alkaline- earth elements are predominant in all samples; therefore, the groundwater in this area is high-qualified. As a result, according to the sameness of qualitative parameters of the groundwaters entering from the adjacent plains and the qualitative parameters of Azna plain, it may be argued that the qualitative effect of the groundwaters entering Azna plain is almost negligible.