Treponema denticola (Td) is a gram-negative anaerobic bacterium closely related to the occurrence and development of periodontal disease and it accounts for a considerable proportion of mature plaque. As a later colonizer of the subgingival plaque biofilm, Td may have complex interactions with earlier and concurrent colonists including symbiotic relationship as while as synergistic or antagonistic effects under the regulation of quorum sensing molecules. Adhesin and coaggregation, mediated by a series of surface molecules, are the basis of the interaction. These interactions are ultimately manifested as gene expression changes in metabolism and virulence, in which are mainly metabolism changes with up- or down-regulation of multiple enzymes related to amino acid metabolism. This article reviews the related researches on the interaction between Td and microorganisms of subgingival plaque.