This review summarizes the recent advances of semi-volatile/intermediate volatility organic compounds studies, including the measurement techniques, S/IVOCs sources, atmospheric behavior and their contributions to organic aerosol formation. The rapid development of mass spectrometry facilitates the S/IVOCs measurements which include on-line and off-line mass spectrometry. The S/IVOCs off-line measurements provide more information about species at molecular level. However, the offline techniques bear the drawbacks of complex pretreatment and low time resolution, which leads to large uncertainties and the limitation to study the atmospheric chemistry processes. The on-line techniques measure the high time resolution molecular composition and gas-to-particle partitioning, and provide more useful information to elucidate the chemical mechanism of the ambient atmosphere. S/IVOCs could be directly emitted into the atmosphere, or formed by the oxidation of volatile organic compounds (VOCs). The major primary S/IVOCs sources are vehicular emission and biomass burning. Previous studies showed that ratios of S/IVOCs to POA are 2.9~8.5 for gasoline engines, 4.5~20.4 for diesel engines, and 0.83~5.57 for biomass burning. The S/IVOCs oxidation could contribute to 34%~76%, 90%, and 80% of the total SOA from the oxidation of gasoline vehicle exhaust, diesel vehicle exhaust, and biomass burning gases, respectively. Model simulation based on field observations showed that the SOA from the S/IVOCs oxidation could account for 40%~85% of the ambient SOA, suggesting that S/IVOCs are unneglectable SOA precursors. In future studies, new techniques are required to be developed to quantify more S/IVOCs species. Concentrations and speciation of S/IVOCs from different sources as well as ambient atmosphere need to be quantified. The combination of field campaign, lab study and model simulation can provide more insights of mechanism of S/IVOCs oxidation to improve our understanding of SOA formation.