The petrochemical complex examined in this work includes a great variety of facilities and factories that emit various odorants. A stationary open-path Fourier transform infrared (OPFTIR) system can be used for routine VOC and odor monitoring. However, when odor episodes occur, only multiple mobile OPFTIR systems are able to identify the odorant sources effectively and efficiently. In this study, N,N-dimethyl formamide (DMF) was found to be the most commonly detected odorant emitted from the investigated petrochemical complex by routine monitoring of a stationary OPFTIR system. Then the sequential deployments of a pair of mobile OPFTIR systems were carried out both upwind and downwind of the different sections of the focal area. The pollution rose plots derived from the data obtained by the pair of mobile OPFTIR systems identified the DMF sources. By conducting correlation analyses on the data obtained from the mobile OPFTIR situated at the downwind location of the DMF emission sources, we found that besides DMF, the dry PU synthetic leather process of plant B was also the major odorant source of 2-butanone, ethyl acetate and isopropanol. The source identification measure developed in this study can be used to clarify possible odorant sources not only for petrochemical industrial complexes but also for other areas associated with various emission sources.