Development　of　river　water　or　development　of　groundwater　may　cause　a　regional　hydrologic　effect　involving　a　large　fluctuation　of　groundwater　level,　spring　exhaustion　and　qualitative　deterioration.　The　paper　suggests　an　equation　of　hydrological　equilibrium　for　the　allocation　of　a　water　source　between　the　artificial　oasis　and　natural　oasis,　and　the　principle　of　macroscopic　allocation　of　a　water　resource　for　protection　of　the　ecologic-environment.　-from　English　summary