Abstract: The detection of an important classe of targets,that is Low radar cross section(RCS) targets(Such as,cruise missiles,Sea skimming anti-ship missiles and stealth aircraft),embedded in heavy clutter is a challenging problem for modern radar technology.The high range resolution capability of stepping frequency radar with its unique waveform and processing is being exploited to solve the problem of detection of low RCS targets in heavy clutter.The fundamental principle and techniques of stepping frequency wideband high resolution radar are introduced.Then the application of stepping frequency radar to solve the problems of clutter free region detection and of folded clutter-free detection of moving low RCS targets in heavy clutter is discussed in this paper.