A control valve assembly includes a housing accommodating an electromagnetic coil unit which is disposed in an in-housing passage and drives a valve element to open and close the in-housing passage. An inflow-outflow member is coupled to the housing, and includes an inflow portion having an inflow passage through which evaporative fuel flows toward the in-housing passage, and an outflow portion having an outflow passage through which the evaporative fuel from the in-housing passage flows. The outflow passage in the outflow portion and the inflow passage in the inflow portion communicate with each other through the in-housing passage.