Abstract: Using the stem segments with dormant shoots of axillary buds of annual silk cotton wood as materials, the effects of different disinfection times, different basic media, selection of exogenous hormones and ratio between hormones on the culture in vitro of silk cotton wood were studied, and the existing tissue culture rapid propagation system of silk cotton wood was optimized. The test results showed that the pollution rate was the lowest and the survival rate was the highest when the axillary bud stem segment of silk cotton wood was disinfected with 70% alcohol for 30s, and then disinfected with 2% sodium hypochlorite for 12min. Using MS medium and adding 5.0 mg/L GA₃+125 mg/L carboxybenzicillin sodium as the primary medium, axillary bud germination rate was the highest and growth status was the best. The suitable subproliferation medium for axillary buds of silk cotton wood was 1/2MS+0.5 mg/L IAA+1.0 mg/L BA, and the effective proliferation coefficient was the highest after 30 days, which was 4.2, and the optimal rooting culture conditions were 1/2MS+0.5 mg/L NAA. The substrate of grass peat:vermiculite:perlite=1:1:1（v/v）was used in the transplanting stage, and 87 silk cotton trees grew well and had intact root systems after 30 days of transplanting, and the survival rate of transplanting was 96.67%.

Key words: Euonymus maackii Rupr, tissue culture, segments with axillary buds, plant growth regulators