Exhaust gas recirculation system for internal combustion engine

An EGR system for an internal combustion engine includes a cooling means (44) disposed in an EGR passage (40) for cooling an EGR gas, an EGR-gas compressor (46) disposed in the EGR passage (40) upstream of the cooling means (44) for compressing the EGR gas, an EGR-gas turbine (48) disposed in the EGR passage (40) downstream of the cooling means (44) for expanding the EGR gas, and driving means (50) for driving the EGR-gas compressor and turbine (46),(48). The EGR passage (40) extends in communication between the exhaust passage (30) downstream of a turbine (34) of a supercharger for the engine and the intake air passage (20) upstream of a compressor (24) of the supercharger. When the EGR system is equipped with a diesel particulate filter (36), the EGR passage (40) is connected to a portion of the exhaust passage (30) downstream of the particulate filter (36).