HULIS (Humic-like substances) are a class of macromolecular compounds which are ubiquitous in fog droplets, clouds, rainwater and aerosols. HULIS have received wide attention. They can affect the energy balance by absorbing and scattering solar radiation in the atmosphere,and also influence climate change indirectly by increasing the formation of cloud condensation nuclei. Moreover, they have significant effects on air quality and human health. This paper summarizes the research progress of atmospheric HULIS,mainly including separation,extraction,analysis; physical and chemical characteristics; concentrations and seasonal variation, as well as sources emissions. The prospect in this field is also discussed.