Based on reviewing the recent research progress, the nomenclature principle, the formation conditions, sedimentary characteristics and controlling factors of hyperpycnal flow are discussed, and some problems and corre-sponding countermeasures are proposed. Hyperpycnal flow can be described as low density, quasi-steady sedimenta-ry gravity flow, which is closely related to suspended particle concentration. The typical deposit or hyperpycnites se-quence is a compound of a basal coarsening-up unit (Ha) deposited during the waxing period of flood, and a top fining-up unit (Hb) deposited during the waning period of flood. The Ha-Hb transition corresponds to the maximum size and marks approximately the peak of the flood. The climate, tectonic activities, sediment supply and relative sea (lake) level change control the evolution of hyperpycnal flow. The climate is the most important factor that influ-ences the size of the rainfall and discharge, which controls the flood magnitude and frequency and directly decides the formation and evolution of hyperpycnal flow. In addition, more attention should be paid to ancient hyperpycnal flow deposits, facies models as well as modern observations and experimental simulation.