Chemical constituents of ground water collected in Akiu area in Sendai city were analyzed. There are 3 samples containing arsenic above 0.01mg·l^-1. In ground water samples, we can detect arsenic at high concentration of sodium ion comparing with the samples where no arsenic was detected. The area in which arsenic was detected is located near a hot spring. The relation between the concentrations of major inorganic conponents and arsenic will be cause by the prolonged contact of ground water with the sediments of the stratum.