An object of this invention is, in an internal combustion engine having of in-cylinder direct injection and port injection, to enable the early elimination of a difference between fuel concentrations of fuel injected from different injection valves that can arise when a mixing ratio of different kinds of fuel contained in the fuel that is used changes significantly. To achieve this, the control device of this invention normally controls a fuel injection amount of each injection valve in accordance with the operating state of the internal combustion engine, while a change arose in the mixing ratio of different kinds of fuel contained in the fuel that is used or while there is a possibility for such a change, the control device controls a fuel injection amount of each injection valve so that fuel is temporarily injected from both the in-cylinder injection valve and the port injection valve.