An exhaust gas aftertreatment system for an engine can perform manual regeneration control for regenerating a particulate removal filter by increasing the engine rotation speed. The system can suppress the engine rotation speed increase while maintaining the exhaust gas temperature required to regenerate the particulate removal filter. The system can set the target engine rotation speed to a first set value when a regeneration instruction signal from a manual regeneration switch is received. When, although the engine rotation speed falls within a predetermined engine rotation speed range including the first set value that is the target engine rotation speed for a predetermined time period, the exhaust gas temperature does not reach the filter's regeneration temperature within the predetermined time period, the target engine rotation speed is repeatedly reset by being increased from the first set value by a predetermined rotation speed.