In this study, firstly, it is aimed to spin PTT (Polytrimethylene Terephthalate) based staple Sustans (R) fibers together with cotton in Open-End rotor yarn production system. In this way, it is aimed to transfer the positive properties of Sustans(R) fibers such as good elasticity, good dimensional stability, low static electrification and soft hand to the staple yarn structure with a high efficiency spinning technique. In this context, using 5 different ratios of Sustans(R)/Cotton blends and 100% Cotton, 6 different rotor yarns with Ne 8.25 (71.6 tex) were produced and the quality characteristics of these yarns were tested. In the study, Sustans(R)/Cotton blends were successfully spun with the Open-End rotor system. As a result, compared to 100% cotton, it was observed that the elongation at break, unevenness, yarn defects and hairiness values were better for yarns containing Sustans(R) fibers, while the strength values were slightly lower. The optimum blend ratio was concluded to be 50/50% Sustans(R)/Cotton for the open-end spinning technique.