From 2021 to 2023, the water quality of agricultural groundwater in Gangwon State was investigated. pH, EC, total nitrogen (T-N), total phosphorus (T-P), NO₃-N, Cl, Na, Mg, K, and Ca were measured in April and July every year and analyzed by land use type, season, and year. pH, EC, and T-P showed little differences regardless of the type of land use and season. Total nitrogen was low in paddy fields compared with the other land use type and showed greater value in July than in April, and tended to increase from 2021 to 2023. The concentrations of Cl, Na, Mg, K, and Ca in groundwater were highest in the greenhouse fields and were slightly greater in July than in April, but there was no clear pattern by year. Groundwater pH exceeded the water quality standard by 10 - 20% in paddy fields, and NO₃-N concentrations in groundwater exceeded by 20 - 40% in upland fields and by 10-20% in greenhouse fields. The results obtained in the study implying that agricultural groundwater in Gangwon State was generally suitable for agricultural purpose.