Two generic types of hybrid drive fitted with Internal Combustion Engines (ICE) have been considered. The first type is a serial one. The second type is a parallel drive system represented by two subtypes: a compact hybrid drive with two degrees of freedom planetary transmission and a split-sectional drive. Based on example hybrid drives for city buses, a computer simulation is an appropriate method as a design tool. Special stress has been put on the compact hybrid drive with a planetary transmission, which seems to be the most advantageous. A serial hybrid drive has also been discussed in detail because currently this solution is the most common one applied in contemporary hybrid buses.