Abstract: In aquatic ecosystem, abundance of various volatile organic compounds (VOCs) are released from algae, including terpenoids, aldehydes, alcohols, esters, aliphatic hydrocarbons, aromatic series, sulfides and halogenides. These VOCs are synthesized from different secondary metabolism pathways, which can be induced by lots of environmental factors. Under environmental stresses, VOCs play an important role in improving algal resistance. When VOCs are released to water bodies, they transfer stress information to the congener algal cells, and the acceptors can prepare to defense the coming stress. For heterogeneous algal cells, VOCs can inhibit their growth via allelopathic effects and keep emitter's competitive advantages. Meanwhile, VOCs can also repel predators to protect algal cells. The VOCs which can not be captured by acceptors volatilize into the atmosphere and take part in the formation of secondary organic aerosols over the waters. To aid in helping the study of algal VOCs, this research review summarizes the types, forming pathways, inducing factors and ecological functions of algal VOCs.