To provide an attachment structure of an inlet pipe 110 which enables easy assembly of the inlet pipe and prevents interference between a vehicle body and a wheel house liner even if a space is small.

In an attachment structure of an inlet pipe 10 for attaching the inlet pipe 10, which is used for injecting a fuel from an oil supply port of a vehicle body to a fuel tank, to the vehicle body, the inlet pipe 10 is installed between the vehicle body 1 and a liner 40, and an attachment clamp 50 is attached to the inlet pipe 10. The attachment clamp 50 includes: a vehicle body engagement part 58 which engages with the vehicle body 1; and a liner engagement part 60 which engages with the liner 40. The attachment clamp 50 allows the inlet pipe 10 to be held on the vehicle body 1 and the liner 40.