HgCdTe thin films have been deposited on CdZnTe/Si(1 1 1) substrates by pulsed laser deposition (PLD). A Nd:YAG pulsed laser with a wavelength of 1064 nm was used as laser source. The effects of CdZnTe buffer layer thickness which varied with the deposition time in the range from 3 to 15 min on the crystalline, morphology and other properties of HgCdTe thin films were analysed. The results show that the crystalline quality and the composition of the HgCdTe epitaxial layer change with the increase of the deposition time of the buffer layer. The CdZnTe buffer layer with a proper deposition time can improve the quality of HgCdTe films, and the HgCdTe films deposited on the CdZnTe buffer layer with the deposition time of 5 min exhibit the best crystalline quality and smooth surface in our experiment.