Toluene is the major volatile contaminant and secondary organic aerosol precursor in atmosphere. A home-made smog chamber is used to study the OH-initiated photooxidation process of toluene in the absence and presence of ammonia. The molecular functional groups of the photooxidation products of toluene are measured by a Fourier transform attenuated total reflection infrared spectrometer. The chemical components of the products are analyzed qualitatively. The experimental results show that there are functional groups such as benzene ring, O-H, C=O and C-O in the photooxidation products of toluene both with and without ammonia and high concentration organic compounds such as cresol, aldehydes and carboxylic acids are contained in the groups. However, in the presence of ammonia, C=N, C-N, N-H and other functional groups corresponding to the imidazole nitrogen-contained organic compounds are also contained in the photooxidation products of toluene. These results provide new experimental basis for the study of the photooxidation mechanism of toluene.