Singlet oxygen is an important kind of reactive oxygen species. It is important in fields that range from materials science to biology and medicine. In this paper, the spectral characteristics and principles of detection of singlet oxygen for a novel fluorescent probe （Singlet Oxygen Sensor Green reagent, SOSG）were summarized, and the state in application for detection of singlet oxygen was also reviewed. Finally, the developing tendency of the SOSG was analyzed briefly.