The electron effective masses, scattering time and mobilities near the Fermi level for the lowest two subbands of the two-dimensional electron gases in a pseudomorphic In0.80Ga0.20As/In0.53Ga0.47As/In0.52Al0.48AsHEMT structure are determined by fitting the cyclotron resonance spectra. The significant enhancement of the electron effective masses, resulting from the conduction band nonparabolicity and the wave function penetration, is observed. The evident subband dependencies of the electron scattering time and mobilities dominated by the alloy scattering and ionized impurities scattering are also discussed.