We investigated the effect of yarn properties and fabric parameters on spirality of dry and fully relaxed single knitted fabrics produced from ring spun cotton yarns. From this study, it was found that the trend of spirality in fabrics, produced from plied cotton yarns, did not coincide wish the general phenomenon of spiralily. In this cases with an increase in tightness factor, the spirality increased in case of dry relaxed fabrics which have tightness factors below a limit point(approximately, TF 16), But, the same phenomenon with fabrics knitted from single yarns showed above a limit tightness factor. Whereas, the double mode trend was found between the fabric tightness factor and spirality in fully relaxed fabrics knitted from mercerized plied cotton yarns. Twist multiplier, yarn count and tightness factor accrued the absolute magnitude of spirality but, machine cut and relaxation treatment did not affect it. We also studied the mechanism of wale skewness in theoretical relation between fabric shrinkage and spirality and the mechanical properties, compression, tensile, elastic-recovery, shear in relationship with the effect of spirality considering for performance of weft single knitted fabric.