Understanding the aquifer hydraulic properties and hydrochemical characteristics of water are crucial for the management plan and study skims in Cambodia, where groundwater has been used for domestic and agricultural purposes in the rural area. In this study, there are two times observed well during late wet season October 2017 and early wet season May 2018. Water Quality Index (WQI) was use to assess of groundwater for drinking and SAR, KR, SSP, MH, Na%, RSC, PI and Gibbs diagram use to evaluated and defined origin of groundwater quality for Agriculture. The overall assessment of groundwater quality for drinking purpose in both late and early wet season shown in excellent and good quality. The water quality can be accepted without the adverse effect of magnesium hazard to irrigation. However, with respect to RSC nearly a half number of samples fell into poor quality for irrigation, and another half number of sampling point were within the medium quality in the late wet season but showed a good grade in early wet season. In term of KR in both seasons, only a few samples are unsuitable for agriculture, and the rest of the sample are a good quality. The potential for a sodium hazard in late wet season increased as the result of the magnesium precipitated from a solution when water is applied to the soil. The causes were confirmed by the results of Gibbs diagram. However, the permeability of soil is not affected by Na+, Ca2+, Mg2+ and HCO - which influence groundwater quality in both seasons. Respect to Na% and EC revealed that all samples of the groundwater samples fell into the good to permissible and excellent to good quality during both seasons. Therefore, Groundwater was found not to be affected by Na+ and EC, and it was suitable for irrigation. Based on the US salinity Laboratory’s diagram, the groundwater for irrigation was found from low to medium in both wet and late wet season in term of conductivity and salinity. In conclusion, the groundwater quality in Chrey Bak catchment is very good for domestic and agriculture however treated groundwater before using still recommend due to some parameters such as arsenic and heavy metal are not included  in this study.