In this paper, wool yarns and the slenderized wool yarns were used as raw materials, and knitted under the same process parameter, many methods of testing were applied to analysis the wearing characteristics, An series of experiments show that there was a significantly improvement in the anti-pilling performance and air permeability, and the stiffness of the sample became smaller, increasing soft and comfort, but it had little effect on crease- resistance. The slenderizing not only improved the spinning count, but also enhanced the knitted properties by the structural transformation, was a good choice to develop the high-grade wool knitwear.