In order to analyze Complementary Code Keying (CCK) performance on the additive white Gaussian noise (AWGN) channel, an idea of M-ary Quaternary Orthogonal Keying modulation (MQOK) is proposed in this paper, based on the analysis of the common traits of CCK and M-ary Bi-orthogonal Keying (MBOK). Again this paper analyzes that MQOK has the merits of simpler demodulation structure and more adaptable to higher data transfer than MBOK and points out that CCK coding modulation is considered a concrete way to realize MQOK. By analyzing the performance of MQOK on AWGN channel in detail, new closed-form formulae for CCK are gained with its own modulation feature. Comparison between the numerical result and the simulation result of Monte Carlo shows that the difference of the required signal-to-noise (SNR) between the numerical and simulation is less than 0.5 dB with any certain bit-error probability and symbol-error probability, which confirms that these formulae are more accurate and practical, and the approach to analyzing CCK performance by MQOK is available.