PURPOSE: To prevent a rich engine stop by automatically holding a choke valve at a lean opening after the cold start of the engine.

CONSTITUTION: This choke valve control device has an interlocking member 5 that engages with the choke valve 3 of an engine, a diaphragm 6a connected to the interlocking member, and a diaphragm chamber 6A partitioned by the diaphragm. Also, the choke valve control device includes a pressure reacting device 6 which, when negative pressure works on the diaphragm chamber, permits the interlocking member to displace the choke valve in an opening direction; communicating passages 18, 19 each having one end communicated with an intake passage 1 downstream of a throttle valve 2 and the other end communicated with the diaphragm chamber; a check valve 15 provided in the communicating passages to stop the circulation of gases from one end to the other; and a flow regulation means 11b provided in the communicating passages to regulate the flow of gases.