Abstract: The social behaviors of the carpenter ant Componotus tonkinus were studied in a semi-natural condition, by observing individual activity. Thirty four workers from a small colony were individually marked. In a total of seven-days observation, the types and frequency of the behaviors displayed by individual ants were recorded. Hierarchical cluster analysis of behavioral frequency data was carried out to determine the labor divisions in the colony. At least 12 behavior types were identified. The colony members were organized around five functional groups：the reproductive group (the queen)，foraging group (10 workers), nest caring group (16 workers), defence group (3 workers) and inactive group (includeing 5 workers).

Key words: Componotus tonkinus, ethogram, labor division