Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a computed tomography method using absorption spectra of water vapor at 1388nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.