Intake system for multi-cylinder engine

In an intake system of a variable air-intake characteristic type for a multi-cylinder engine, an intake air-dispensing box (30) is comprised of a dispensing box body which includes an intake air inlet, first and second intake branch pipes (38R,38L) and one of halves of a partition wall (35a) and which has an opening provided in its outer wall opposite from the first and second intake branch pipes to extend between first and second dispensing chambers (37R,37L), and a lid (44) detachably coupled to the dispensing box body to close the opening and having the other half of the partition wall. The lid is made of a light alloy by casting, and a valve bore (40) and bearing bores (54) for supporting a valve shaft (53) of the on-off valve are defined in the other half of the partition wall. Thus, it is possible to carry out the maintenance of the on-off valve only by removing the lid disposed outside the intake air-dispensing box from the box, leading to an enhancement in maintenance property.