A hip joint simulator was employed to predict the clinical wear behaviour of carbon/carbon （C/C） composites with needled carbon cloth preform and carbon felt preform. Wear particles generated from the two kinds of C/C composites were isolated and characterised by the size distribution and morphology. The evolvement of wear particles in the hip joint simulator was proposed. The results show that the wear particles from two kinds of C/C composites have a size ranging from submicron to tens of micrometers. The wear particles have various morphologies including broken fiber, fragment fiber, slice pyrolytic carbon and spherical pyrolytic carbon. C/C composites with needled carbon cloth preforms have larger size range and more broken fiber particles and slice pyrolytic carbon particles in comparison with C/C composites with carbon felt preforms. The evolvement of pyrolytic carbon particles is caused by surface regularization, whereas, the evolvement of carbon fiber particles is related to stress direction in the hip joint simulator.
