A vehicle drive system with a vehicle electric power generation control device is configured to prevent a drive belt between an engine and generator from slipping without causing the output of the generator from declining. When the target load torque Tg* of the generator is limited to the maximum transmittable torque value Tslip in order to prevent the belt from slipping, the engine rotational speed Ne and the generator rotational speed Ng are increased by downshifting the automatic transmission 4 to a lower gear ratio.