Abstract: Based on vector antenna, a novel approach to the three-dimensional joint modulation of the phase, polarization amplitude, and polarization angle parameters of an electromagnetic signal is presented. Its implementation strategy is also given while the proposed three-dimensional joint modulation constellations and the constellation point distributions are discussed. The calculation method of the bit error rate(BER) of the proposed three-dimensional joint modulator and demodulator is also given. Both the analysis and the simulation results show that a high information transmission rate can be kept while a low bit error rate is obtained by the proposed method.