The control apparatus of the present invention is applied to a hybrid vehicle having an internal combustion engine that is capable, during operation, of changing over its operational mode to lean combustion or to stoichiometric combustion. The control apparatus preferentially selects an operational mode having high system efficiency in relation to the requested power, and selects the stoichiometric combustion mode (S104) when, under the specific condition that the system efficiency is higher in the lean combustion mode as compared to the EV mode and moreover is lower in the stoichiometric combustion mode as compared to the EV mode, also the temperature (Tnc) of an exhaust purification catalyst is less than or equal to a first predetermined value (Tα) (S101, S102).