ABSTRACT
Co-occurrence network of major MeSH terms and all MeSH terms was constructed respectively with MEDLINE-covered pharmacological literature as its example.The degree, closeness and betweenness of centrality in different nodes of the two co-occurrence networks were analyzed , the distribution of scale-free properties in the two co-occurrence networks was tested, the small-world effect of the two co-occurrence networks was identified by comparing their overall properties ( average distance and clustering coefficient ) , which showed the scale-free properties and small-world effect of the two co-occurrence networks.The co-occurrence network of all MeSh terms could thus be used in analysis of network properties while that of major MeSH terms could thus be used in analysis of subject contents.