An operating method of an exhaust gas aftertreatment system including at least a particulate filter for retaining soot from the exhaust gas of an engine and a deNOx catalytic converter for reducing nitrogen oxide in the exhaust gas of the engine is provided. Operation regimes of the particulate filter and of the deNOx catalytic converter are synchronized with respect to each other for performing regeneration of the particulate filter while the catalytic converter provides a nitrogen oxide conversion efficiency above a predetermined limit.