Geothermal is a kind of clean energy source,and is also renewable in most cases.Although geothermal development may bring out important social,economical and environmental effects,it is also possible to have noticeable impact on the environment.Therefore,it is essential to have proper management to the geothermal systems under exploitation.According to the principle of sustainable development,the definition for the allowable production from a geothermal system may be stated as the constant and maximum amount of energy can be exploited under the condition that the reservoir pressure is properly controlled,and without causing serious environmental problem.If the production from a geothermal system is not more than its allowable production,it can be referred as sustainable exploitation; otherwise it is called excessive exploitation.To ensure the sustainability of a geothermal system,it is important to set up and update the reservoir model of the geothermal system,to have a proper monitoring program,and to carry out reinjection.