There has been no previous description of the pathological features of Alzheimer's disease and little description of Alzheimer-type changes in Chinese brains. In this study, we examined the brains of 17 cases of Alzheimer's disease and concurrently 95 consecutive autopsy cases of non-demented patients aged above 60. Six standard regions of the brains were stained for beta-amyloid immunostaining, Bielschowsky and Bodian. Neuritic plaques, neurofibrillary tangles and diffuse plaques were quantified as per mm2. The Alzheimer's disease brains exhibited a marked increase of neurodegenerative changes over the non-demented brains. Plaque counts were similar to those proposed by Khachaturian (1985; Arch. Neurol. 42: 1097-1105) and CERAD, although the distribution of tangles was more variable with some regions of the neocortex containing few or no tangles. For the non-demented brains, overall neuritic plaques were seen in 31% and neurofibrillary tangles were seen in 42% of cases, with the overall plaque score being 1.8 per mm2 and tangle score being 0.7 per mm2. No age-dependent variation of plaque count and tangle count could be demonstrated in this group of elderly brains. Comparison with similar studies of Caucasians suggests that neuritic plaques and neurofibrillary tangles were less frequently encountered in aging Chinese brains than among the western populations.