An intake system of an engine including an intake manifold, which includes an intake air introducing pipe and a plurality of independent intake pipes, is provided. Each of the independent intake pipes has an arc shape surrounding the intake air introducing pipe from outside with a space. A first independent intake pipe is curved more in the cylinder lined-up direction than a second. From the side in the cylinder lined-up direction, the arc shape of the second independent intake pipe is more distant from the intake air introducing pipe. To a first member constituting part of the intake air introducing pipe, a second member is joined to form the arc shape of the first independent intake pipe. A third member disposed radially outward from the first member is joined to the second member to form the arc shape of the second independent intake pipe.