A catalytic converter consists of an exhaust gas inlet, an exhaust gas outlet, and a catalytic reactor located between the inlet and the outlet for reacting with the exhaust gas discharged by the internal combustion engine of a motor vehicle, so as to reduce air pollution. The exhaust gas inlet is provided with a vortex generator for causing the incoming exhaust gas to flow in a helical path into the inlet and than the catalytic reactor in which the exhaust gas reacts uniformly and thoroughly with all cross-sectional areas of the catalytic reactor of the catalytic converter.