Abstract: Battlefield electromagnetic environment is becoming more and more complex, which seriously affects the normal use of weapons and equipment. Active jamming is one of the most important menaces, and is the research object of this paper. According to the different characteristics of deception jamming and barrage jamming, this paper analyzes them from three aspects of time, frequency and energy, and presents the method of quantitative description of interference. It uses the energy spectrum and the formula of energy calculation to complete the characterization of barrage jamming, adopts the correlation algorithm and puts forward the concept of degree of coincidence spectrum to complete the characterization of deception jamming. The feasibility of the method is verified by Simulink/Matlab simulation. This quantitative description method is helpful for the evaluation of electromagnetic environment in battlefield.