Eight species of parids commonly occur in the mountains of northern Sichuan Province, People's Republic of China. They represent four monophyletic groups regarded by some authorities as genera, but more traditionally as subgenera of the large genus Parus. To test the competition-based hypothesis that less closely related species are more likely to co-occur, we used specimens and observations obtained in October 1989 and May 1991 to delineate the morphology, elevational range, and habitat associations of each species in this rich assemblage. A morphometric cluster analysis did not support the assumption that phylogenetic similarity predicts morphological and hence ecological similarity. Up to five species commonly co-occurred in mixed flocks, as in Europe (where five subgenera are represented), but a randomization test showed that community assembly was random with respect to subgenus. On the other hand, for the entire data set (P = 0.05) and during spring (P = 0.07), species in the same morphometric cluster were less likely to co-occur than were species with dissimilar morphology. It appears, therefore, that competition between species of similar morphology may play (or have played) some role in structuring assemblages of parids during the breeding season in this area. For this reason, more detailed studies of the parid assemblage in this area are recommended.