This study applies a method of author co-citation analysis to examine intellectual structure of political communication study. Primarily based on the number of their articles in communication journals, fifty-one influential authors are selected from active members of the Political Communication Divisions of the International Communication Association (ICA), the National Communication Association (NCA), and the American Political Science Association (APSA). The results of the multidimensional scaling analysis and cluster analysis of these 51 selected authors' co-citation patterns show that intellectual fragmentation exists in political communication research; scholars with different academic backgrounds have their specialities of using a particular research approach to study certain subjects in the field; scholars do not have much information exchange, and thus they are intellectually separate and confined within the boundaries of each fragment. The findings of this quantitative study complements and cross-validates the assessment made by other traditional qualitative reviews about the field.