The effects of low temperature $O_2$plasma on the mechanical properties, dimensional stability, and hand of wool fabric have been evaluated. Low temperature $O_2$ plasma treatment modified the surface of wool fiber physically and chemically. The SEM(scanning electron microscope) photographs of wool fabric treated with low temperature plasma of different power levels revealed some changes in the cuticle. Partially lifted or broken and less distinct scale edges were found on the modified fibers, especially on the fiber surface treated with plasma of 150 W power level. By ESC of narrow high-energy resolution scans of the $S_{2p}$ level, a second peak at 168 eV was detected, which indicated that cysteic acid groups were induced in wool by $O_2$plasma treatment dramatically improved the dimensional properties of wool fabrics. Wrinkle recovery angle after plasma treatment was slightly decreased due to increases in frictional components of wrinkling, such as friction coefficient and bending hysteresis. Plasma modification of the fiber surface caused a significant increase in the frictional coefficients of wool, in both with-scale and against-scale directions. This alteration of surface friction explains the apparently harsher handle, decreased tear strength and increased grab break strength imparted by plasma modification.n.