Previous evidence had revealed gender differences in perception of pain and its socialization. The present research studies gender differences by mapping the central structure core in social representation of pain. Eighty males and eighty females participated in a free evocation task for collecting cognitive elements of “pain.” By defining the elements as nodes and their co-occurrences as lines, structural characteristics of social representation are analyzed by network analysis. Females have a central structure core in their network structure of social representation of pain. In contrast, males have no such core. These results suggest gender differences in socialization processes around the concept of pain and extend practical methods for studies of the central nucleus theory of social representation.