As an important factor, complex electromagnetic environment has been considered in radar operational capability evaluation. This paper constitute the radar operational capability index system about an antiaircraft alert radar, description method of radar electromagnetic environmental complexity has been put forward, and the radar operational capability evaluation model, which based on genetic neural network has been modeled. At last, as an example, the impact of radar operational capability in complex electromagnetic environment has been analyzed. The result shows that the radar operational capability which has been influenced by the battlefield complex electromagnetic environment is effect and welled up by several factors. With the battlefield complex electromagnetic environment jam intensity increase, the radar’s phase and whole operational capability decline gradually.