Yarn formation process consists of several sequential unit processes and the ring process Is the final stage determining the product quality and the manufacturing cost that outweighs other unit processes. Therefore the technological developments on the ring spinning method are focusing on the improvement of spinning speed and high quality product. But these technological targets are limited by the fact that the spinning tension increases excessively due to the friction between the running yarn and the traveller, including the friction between the traveller and the ring as well. This research was conducted in order to obtain the behavior of the yarn spinning tension that is variable during cops building. The results showed that the spinning tension changed reciprocally to the yarn forming diameter of the cop on the ring frame and in a quadratic form to the ring rail position. In addition, the research suggested that a zone of ring-rail position existed where the spinning tension reached, a minimum throughout the ring diameter. The spinning tension changes drasticallg when the process begins, i.e., for the small diameter of the cops.