The hazard of forest insects and diseases has been worsening in our country and cause great damage each year. A principal factor is that early and mid-term forecasting of could not be done accurately to controll the hazards at the initial stage.Although it’s still far away from predicting accurately the occurrance and development process of forest insects and disease

it’s possible to detect the early hazard spots through the techniques of remote sensing so that the damage can be reduced greatly.A methodology to monitor early spots of forest insects and disease with TM data is discussed in this paper

and it has been proved very efficient.Satellite remote sensing has provided a good instance for macroscopic monitoring and warning of severe forest insects and disease in our country.