A new scheme of orthogonal multicarrier CDMA based on wavelet packet functions is proposed. Transmitted data bits are serial to parallel converted to a number of parallel sub-channels. On each sub-channel each bit is spread by PN code. Each chip on different sub-channel modulate different wavelet packet functions. Good properties of wavelet packet functions ensure that the system can suppress multipath interference, inter-subchannel interference (ICI) and multiple access interference (MAI) effectively. The system performance is investigated for a multipath, slow Rayleigh fading channel. The performance advantages of the system over that based on DFT are demonstrated by both analytical and simulation methods.