A new design method to generate pulses for ultra-wideband (UWB) communication systems is presented. The systematic searching method is based on the linear combination of a number of Gaussian derivative pulses to form one single pulse whose power spectral density (PSD) not only conforms to the FCC spectral mask, but also effectively exploits the allowable bandwidth and power. In addition, the effect of pulse shaping on the mitigation of multiuser interference (MUI) is also taken into consideration in the proposed pulse shape design method. In particular, the authors develop a parameter called normalized mean-squared partial pulse correlation, which only has relation with the pulse shape and can directly affect the signal-to-noise ratio (SNR) of the receiver in a multi-user environment. By choosing a pulse which minimizes this parameter, the authors obtain the desired pulse shape. Compared with the widely used single Gaussian derivative pulses, the pulses they designed achieve better bit error rate performance in both single link and multi-user TH-PPM and TH-BPSK UWB communication systems.