Clouds have important effect on the Earth Air system radiation budget.This paper investigates the relationship of satellite measurements with global radiation and net radiation in clear and cloudy skies by using radiation theory.We develop some models estimating global radiation and net radiation by using satellite data,and seperal best models of them are selscted.These models can be used to estimat the global and net radiation in clear sky and cloudy sky,thus remedying the stortage of radiation data.