To provide a clip installation structure for a writing implement which keeps the structure simple and easy to assemble and enables a clip to be securely attached to a shaft tube in a rotatable manner.

Latching holes 14 are formed on the rear end sides of bent parts 12 on both sides of a clip body 11, and first inward latching shoulders 15 are formed on the rear end of the clip body. Turnable spindles 23 are provided in an projecting manner on installation walls 22 on the rear end side of the shaft tube, and second latching shoulders 24 are formed on the rear ends of the installation walls. The turnable spindles are engaged with the latching holes of the clip, and an approximately U-shaped spring member 3 is pressed into a gap between the installation walls 22 so that either end of the spring member 3 is engaged into the first latching shoulders or the second latching shoulders, thereby the rear end of the clip snaps to open. Inward spring member non slip fall prevention walls 16 are formed closer to the leading edge than the latching holes of the clip.