This　paper　studies　the　channel　capacity　with　respect　to　Cosinusoid　Gaussian　serial　pulses　of　MPPM-TH-UWB　communication　systems　under　additive　white　Gaussian　noise　(AWGN)　channel.　It　mainly　makes　comparison　between　optimum　combined　cosinusoid　gaussian　pulse　and　2nd　devative　Gaussian　pulse　conforming　to　the　FCC　regulations.　The　simulation　results　demonstrate　that　the　capacity　is　influenced　by　variance　of　various　pulses　autocorrelation　function.　This　conclusion　is　helpful　for　the　pulse　analysis　and　selection　for　UWB　systems.　©　2011　IEEE.