Singlet oxygen (¹O₂) is widely considered to play a major role in photodynamic therapy (PDT), and thus an increasing attention has been focused on the direct detection of ¹O₂ near-infrared luminescence around 1270 nm for PDT dosimetry. A new sensitive detection system is developed to directly measure the temporal and spectral resolved ¹O₂ luminescence spectra. The triplet state and ¹O₂ lifetimes of Rose Bengal as a model photosensitizer in different solvents are determined, and the obtained results agree well with the published data. Our detection system has the potential application in ¹O₂ luminescence-based PDT dosimetry.