To provide an exhaust emission control system mounted on a working vehicle which withholds the regeneration operation of an exhaust emission control device when an operator is not seated on the driver's seat.

The exhaust emission control system 100 mounted on the working vehicle includes the exhaust emission control device 20 installed in the exhaust system of an engine 50 and having a DPF 22 therein; and a control device 30 which executes the regeneration operation of the exhaust emission control device 20 when the collection amount of particulate matter in the DPF 22 exceeds a first set value, and stops the regeneration operation of the exhaust emission control device 20 when it becomes smaller than a second set value during the execution of the regeneration operation. The exhaust emission control system includes a seat switch 16 for detecting the seated state of the operator on the driver's seat 15. When the collection amount of the particulate matter in the DPF 22 exceeds the first set value, the control device 30 withholds the regeneration operation of the exhaust emission control device 20 when the seat switch 16 does not detect the seating of the operator.