To provide a connection structure with a screw-type joint capable of preventing cracks at a neck part even when receiving vibration generated repeatedly.

In a pipeline 10, a seal housing groove 13 is formed on a pipe end face 12 of a pipeline body 11. An O-ring 30 is housed in the seal housing groove 13. When the pipeline 10 is connected to a connected member 20, the O-ring is crushed so as to prevent leakage of differential oil from between the pipeline 10 and the connected member 20. Also, the pipe end face 12 of the pipeline body 11 is in contact with a receiving face 24 of a housing 21 without any gap. Accordingly, when bending moment M is generated on the pipeline 10 due to vibration of the connected member 20, an external force transmitted to the connected member 20 (housing 21) from the pipeline 10 by the bending moment M is received in an entire region of a contact face.