Bamboo charcoal shows many advantages such as: moisture-proof foul smells reduction, the release of negative ion and far infrared ray, keep warm etc. For the purpose of increasing disersification, comfortable and beautiful feeling of the fiber efficiency, it already popularly applied to textile industry. This study used the elastic fibers as core yarn that was covered with polyester textured yarn contained bamboo charcoal to produce covered yarn. Elastic yarn was draw for suitable ratio and then covered with polyester yarn to form covered yarn, different draw ratio worked by changing roller speed, adjust twist number by controlling take up roller speed and twister speed of covering machine to get ideal stretch power were studied. Experiment results indicated that maximum break strength (4.52gw/denier) that when the speed of the rotor is 6000rpm while drawing ratio at 350%, twist number 2turns/cm. Maximum breaking elongation (24.57%) could get at speed of the rotor is 4000rpm when drawing at 350%, twist number 4.5turns/cm.
