SOA (secondary organic aerosol) is an important component of aerosols, which forms from the chemical conversion of volatile organic compounds (VOCs) in the atmosphere and imposes great influence on weather, climate, atmospheric environment, and human health. However, so far the exact chemical composition and formation mechanism of SOA are still not clear. The approaches for the study of SOA include laboratory simulation of chemical conversion processes of individual species or multiple species, observational study of the chemical composition, sources and sinks, multiple scale analysis of SOA from the real atmosphere and hindcast and prediction studies of the formation of SOA in the atmosphere by numerical simulations. Laboratory studies are a main tool for obtaining basic parameters of the SOA formation and examining the formation mechanism for SOA. Over the last several decades, particularly in the recent five years, great progress has been made in the research of formation of SOA, including further understanding of SOA precursors, formation mechanisms for SOA and its influencing factors. This paper briefly reviews the progress on these aspects with a focus on the research conducted by Chinese researchers. In the study of SOA with indoor chamber system in the laboratory, the development and characteristics of the chamber system are summarized. The wall effects related to the chamber reactor are discussed. The research progress on the formation of SOA from the conversion of different kinds of organic species, such as terpenes, aromatics, and light-weight molecules are emphatically reviewed. In the study of SOA by flow reactors and other reactors, the main chemical composition and the role of SOA formed from VOCs on the surface of particles and in the liquid phase are particularly described.