An internal combustion engine cooling system includes: an internal combustion engine; a water pump for circulating a fluid; a flow path for the fluid circulated at least between the internal combustion engine and the water pump; a first sensor disposed on the flow path through which the fluid flows from the internal combustion engine to the water pump; a first flow path provided with a fluid cooling means; a second flow path provided with a heat exchange means; a first valve provided on the flow path and configured to control inflow amounts of the fluid into the first flow path and the second flow path; a second valve provided on the second flow path and configured to control inflow of the fluid into the second flow path; and a controller for performing failure determination of the second valve based on a detection result of the first sensor.