To provide a piecing mechanism capable of eliminating tension unevenness during piecing adjustment and piecing bundle according to yarn feed/yarn speed on a downstream side, eliminating a considerable yarn speed error between the yarn feed/yarn speed on the downstream side and a piecing device during piecing, eliminating problems of looseness of yarn during piecing through a wind force and tension unevenness, etc. of yarn through a centrifugal force and eliminating yarn breakage while piecing during yarn feed on the downstream side, and a sample-warping machine using the piecing mechanism.

This piecing mechanism includes the piecing device for piecing yarn on upstream side and downstream side, a yarn storing device for storing yarn on the downstream side, and a yarn tension adjusting device for performing a tension control of yarn between the piecing device and the yarn storing device. The yarn storing device includes a storage drum on which yarn is wound, a driving means for driving the storage drum and a speed control means for performing a speed control of the storage drum.