Abstract: An exhaust emission control system of an engine is provided, which includes a NOx catalyst disposed in an exhaust passage for storing NOx within exhaust gas when an air-fuel ratio of the exhaust gas is lean, and reducing the stored NOx when the air-fuel ratio is approximately stoichiometric or rich. A processor executes a NOx reduction controlling module for performing a NOx reduction control in which a fuel injector performs a post injection to control the air-fuel ratio to a target ratio, and an EGR controlling module for controlling an EGR valve to recirculate EGR gas. In the NOx reduction control, the EGR controlling module controls an opening of the EGR valve to a target opening smaller than when the NOx reduction control is not performed. The NOx reduction controlling module starts the control after the EGR valve opening is controlled to the target opening.