Abstract: Abstract：It was studied on different effects of MS, NAA, IBA and AC on roots growth in vitro of Yucca elephantipes by using the orthogonal design. The results showed that MS or IBA had the great significant. It was indicated that the optimizing medium was 1/4MS + NAA 0.8mg/L + IBA 2.0mg/L +AC 3.0g/L for roots growth in vitro of Yucca elephantipes.