The present invention is intended to provide a control system for an direct injection
internal combustion engine capable of effectively reducing the amounts of both
HC and NOx exhausted from a combustion chamber during a period from the start of
the engine operation to the stop of the engine operation. It comprises an external
EGR passage (11) for returning a part of exhaust gas from an exhaust pipe
(10) to an intake pipe (5), an external EGR control valve (12)
for controlling an amount of exhaust gas returned to the external EGR passage (11),
and a valve timing varying mechanism (9A, 9B) for varying timing
of opening and closing at least one of an intake valve and an exhaust valve. An
ECU 100 controls the valve timing varying mechanism (9A, 9B)
to always return internal EGR gas in an operation region where exhaust gas recirculation
is required, and controls the external EGR control valve (12) to return
exhaust gas in a combination of internal EGR and external EGR when an internal
EGR rate provided by the valve timing varying mechanism (9A, 9B)
is not sufficient to satisfy an EGR rate demanded depending on an operation state.