Abstract: In this paper，Lilium brownii var. viridulum was selected as materials，multiplying medium was selected for improving the multiplication coefficient，and bulbs development were researched by using different root swelling agent and Brassinolide（ BR）. The results showed that the optimum medium of multiplication for the clustered shoots of L. brownii var. viridulum was MS+6-BA 2.0 mg/L+NAA 0.25 mg/L，the multiplication coefficient reached 7.3. The medium that contented BR 1.0 ml/L was the best treatment for the cluster shoots，because the whole plant weight and bulb weight were 1.65 g and 1.33 g，respectively，which improved by 33.33% and 29.35% than those of control，respectively. The bulbs of L. brownii var. viridulum reached 14.65 g and 14.91 g by using 2.0 g/L root swelling agent and 1.0 mL/L BR ，respectively，which were 108.8% and 110.7% of those of control. In the same time，the amino acid contents were 108.0% and 108.5% of that of control，and protein contents were 114.4% and 113.0% of that of control. Therefore，the optimum medium of multiplication for cluster shoots of L. brownii var. viridulum was MS+6-BA 2.0 mg/L+NAA 0.25 mg/L，and the pseudobulbs yield，amino acid content and protein content of L. brownii var. viridulum were improved after treated by 2.0 g/L root swelling agent or 1.0 mL/L BR， respectively.