Abstract: Symmetric Raised Cosine Keying (SRCK) modulation is a new binary digital modulation method. The information is sent by the different polar of the frequency change waveform. For continuous phase and smoothing frequency change, the SRCK signals have characteristics about high energy concentration, high bandwidth efficiency and good resistance to amplitude fading. In order to analyze the communication performance of the SRCK modulated signals, the correlation of the SRCK modulated sample waveforms is deduced, and an analytic formula with the Bessel function is obtained. The main factors of effecting the correlation value changes are analyzed. Orthogonal symmetric raised cosine keying modulation method is proposed, and the characteristics of the signals are analyzed. An efficient modulation communication system is provided for next generation wireless communication.