Plant hormone metabolism provides plants with a means by which they cantransduce signals and adjust growth and development. Although the role of plant hormones on the growth and development of terrestrial angiosperms is well established, little is known about them aquatic plants. This paper reviewed recent researches on hormones in aquatic plants, including hormone diversity, ecophysiological role, biosynthesis pathway, target site, action mechanism and their interaction with each other. Five classical hormones (IAA, GAs, CTKs, ABA and ethylene) have been proved commonly to exist in aquatic plants as well as terrestrial plants except that Potamogeton pectinatus does not produce ethylene. These hormones play some different physiological roles in aquatic plant form land plant. They take active roles in eliciting the structural differentiation in aquatic plants. ABA induces the formation of aerial leaves while CTKs and GAs favor the formation of submerged ones. Asexual propagules, including turions and tubers, are induced. In pathway, C₃-like trait may be replaced by C₄-like trait under the control of hormones. The role of ethylene in aquatic plants is prominent and different from that in terrestrial plants. As ethylene diffuses more slowly in water than in air, higher concentration of ethylene accumulate in aquatic plants, thereby inducing shoot elongation. Research on the biosynthesis pathway, mechanism of action and interaction among types of hormones is limited in aquatic plants, but may be more complex than in terrestrial plants. Moreover, hormones have been proved useful for restoration of native species or management of exotic aquatic plants although their application is limited to small areas at present. To promote their study in the laboratory and practical use in management, we suggest new fields for research and use in future, including (1) discovering new effective plant growth regulators for aquatic plants and (2) restoration of aquatic plants by the induction of stress resistant gene expression under hormone control.