Starting with the connotation of electromagnetic environment in the modern battlefield and taking the electromagnetic signal emerged by radar and radar countermeasure equipment for example, this paper analyzes the characteristics of electromagnetic environment in war and its effect on operations.Aimed at the electromagnetic problems encountered by radar, some reasons are investigated from aspects of mutual interference of equipment and electromagnetic attack on radar.In order to show the complex multiple factors that may restrict the electromagnetic battlefield game, characteristics of such typical radar countermeasures tactics as stand-off jamming, escort jamming, self-screening jamming, disposable launch jamming,and anti radiation are summarized respectively.Moreover, the tactical application method of various jamming types is studied, as well as several effective radar counter-countermeasures, including frequency agility, pulse compression,side lobe suppression, and automatic frequency selection.Finally, the paper points out the critical importance of technology interaction between radar and electronic warfare equipment.