To provide an intake pipe structure for an internal combustion engine, capable of properly assuring a variable intake function with a simple structure without requiring a selector valve or the like for changing an intake passage mode.

This intake pipe 1 comprises an intake passage 2, a first intake passage 2c and a second intake passage 2d which are branched by a bulkhead 2b provided inside the air intake passage 2 to be provided in parallel. The intake passage 2 branched into the first intake passage 2c and the second air intake passage 2d so that the air sucked from the intake passage 2 may preferentially flow into the first air intake passage 2c is offset on the first air intake passage 2c side to be connected.

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