Morphological changes in spine shapes have been implicated as indications for physiological or pathological status. To investigate the normal distribution ratio of spine shapes of rat Purkinje cells, morphological analysis was conducted using high-voltage electron microscopy following Golgi impregnation. Spines were classified into thin, stubby, mushroom, branched, and unclassified type by their distinct morphological features. In the tertiary branches of Purkinje cell dendrites, proportions of each category were 69.11+/-1.38% (thin), 13.5+/-1.23% (stubby), 10.45+/-0.74% (mushroom), 2.21+/-0.31% (branched), and 4.73+/-0.52% (unclassified). These results suggest that dendritic spines of Purkinje cells may tend to cluster in defined groups by shapes implying that different spine shapes could reflect different functional roles. This classification could be applied for further study of spine plasticity in various conditions.