Tottori Hot Spring belongs to a muriated sulfated spring with twenty seven spring sources in 1949. But since 1949 about ten new springs are permitted to bore by the Prefectural Council on Hot Springs. And so the total amount of flow or the capacity of Tottori Hot Spring became a matter of concern among the citizens of Tottori. By the relationship between the chloride and sulfate or chloride and bicarbonate content of spring waters, it was concluded that all thermal springs of Tottori City derive from a same thermal source. As Tottori Hot Spring did issue out without aid of a pump in former days and nowadays does not, it seemed possible that a gradual fall of thermal water level took place and was golng On. ln most of Tottori Hot Springs a moter of one horse power was enough to pump up the thermal waters. But it occured that in one of the newly bored spring a pump With a three horse power motor was found being in use without permission of the Council. So the author took the chance of investigating the influence of the pumping of the new spring on the temperature, amount of flow, and chemical composition of waters of the surrounding springs. And he found that pumping up with three horse power motor could lower the water level and change the Chemical composition of some of the sorrounding springs and warned the Council of the danger of an abuse of permission to bore springs.