Aimed at the problem of complexity of jamming environment and diversity of anti-jamming measure, a new method of effectiveness evaluation for terminal guidance radar of anti-ship missile was put forward. Successful jamming probability calculation model and effectiveness evaluation model were built by the means of probability analysis, and the effectiveness evaluation steps was given, which set the stage for ration evaluation of terminal guidance radar effectiveness of anti-ship missile. Result shows that the model can offer base for achieve ration evaluation of terminal guidance radar of anti-ship missile.