To provide an injection amount control device for an internal combustion engine, can improve drivability and prevent an increase of a misfire rate by improving the correcting accuracy of a learning value for the aging deterioration of an injector.

An ECU obtains a vehicle travel distance from a RAM (Step S11), and determines whether it is a learning timing for learning injection or not (Step S12). When determining that it is the learning timing (Yes in Step S12), it calculates a learning value KG1 (Step S13). Meanwhile, when determining that it is not the learning timing (No in Step S12) the ECU calculates a learning value difference KG produced by a difference between a travel distance at a previous learning timing and a current travel distance in accordance with the pre-estimated deterioration trend of the injector (Step S15) and updates a learning value KG using a value obtained by adding the learning value difference KG to the learning value KG1 (Step S16).