Abstract: In this paper, the development and innovation course of various new technical systems of radar is introduced since its birth. Basic model for presenting the relationship between radar electromagnetic signal waveform and target information is put forward. On the basis of that, theoretical foundation of development and innovation for radar technical system is discussed. It is considered to find and select electromagnetic signal waveforms (time domain, space domain, polarization domain or combined domain) which are able to collect new target information and form new signal processing methods for echoes from electromagnetic signal waveform as well as extraction methods for target's new information is the theoretical foundation of development and innovation for the technical systems of radar system.