In this study, the effects of different fiber cross-sectional shapes and yarn linear density values on Partially Oriented Yam (POY) and textured yarn characteristics have been examined. In experiment, five different cross-sectional shapes, namely round, trilobal, tetra, hexsa and octolobal and two different linear densities have been used and tenacity-elongation. crimp and shrinkage tests have been applied to the yams. As a result, the round and octolobal cross-sectional shapes lead to yam formation with high tenacity and breaking elongation, on the other hand trilobal and hexsa cause low tenacity and breaking elongation. The round cross-section has provided yam formation with high crimp and low shrinkage, the hexsa and tetra cross-sectional shapes have caused lower crimp and high shrinkage. It was also observed that the increase in the linear density has caused a decrease in yarn tenacity, however this has increased the crimp and shrinkage behaviours of the yarns.