An intake system for an internal combustion engine is provided which
comprises a variable valve control apparatus capable of variably and
continuously controlling the amount of intake air of an internal
combustion engine by varying valve lift characteristics of an intake
valve, a collector fluidly connected with a plurality of intake passages
for cylinders of the internal combustion engine, and a pressure control
mechanism for producing within the collector a vacuum that increases with
increase of one of the amount of intake air, engine speed and engine load
of the internal combustion engine.