The amplitude and energy distributions of the voltage and current in the different frequency bands can be obtained by analyzing the frequency spectrum of standard lightning currents.The general lightning currents of 8/20(μs)and 10/350(μs),return stroke of 0.25/100(μs)and the testing currents recommended by national standardization(10/200(μs),4/300(μs),1.2/50(μs),10/700(μs))are selected to compute the frequency spectrum of amplitude and energy by the use of the continuous Fourier analysis,and they are compared with those of natural lightning radiation field.The results show that the amplitude and energy of lightning currents mainly appear in the range of low frequency,and amplitude frequency is less than 1MHz,but the frequency spectrum of the energy is from several kHz to several hundreds kHz.The half peak value time(t₂)of currents is a crucial factor in the frequency spectrum distribution of amplitude and energy,which determines the abundance of currents' wave in the parts of low frequency.The results should be an important reference in the application and design of lightning protection.