Abstract: Harmful algal blooms (HABs) are one of the major marine pollution concerns in China.In this study, we summarized the current theories on the mechanism of HABs.Mitigation measures are also discussed accordingly.We suggest that more studies should be carried out on the mechanisms of the HABs and focused on the conceptual model of combined catchment, estuaries and coastal areas.In addition, considering the complex situation in coastal regions and uncertainty in ecosystem evolvement, except for ecological restoration, monitoring remains necessary as eutrophication management strategy.