A fuel injection control apparatus of an internal combustion engine, which can appropriately control the amount of fuel injection from an in-cylinder injection valve so as to achieve a desired air-fuel ratio, regardless of the operating state of the internal combustion engine, is provided. The fuel injection control apparatus comprises: an additional injection means which, when determining that the operating state of the internal combustion engine is a transient state, allows the in-cylinder injection valve to inject a fuel amount conformed to a changing intake air amount; and a subtraction means for subtracting a minimum fuel amount, injectable from the in-cylinder injection valve, from a fuel amount to be injected, before injection by the additional injection means is performed.