Objective: To compare physical properties and in vitro dissolution of Dracaena cochinchinensis powder with different particle size. Method: Comparison study of for D. cochinchinensis with different particle size was adopted

including apparent characteristics

flowability

extractive

moisture content

hygroscopicity

in vitro dissolution and so on. Result: Physical properties and in vitro dissolution of D. cochinchinensis had a certain changes after been ultrafine grinded.Along with decreases of particle size

the powder appeared aggregation gradually and the colour shallowed

the grainy disappeared;The flowability was worse

the content of extract and water increased

the hygroscopicity strengthened

the in vitro dissolution increased. Conclusion: Comparing with the powder of 80 mesh

physical properties and in vitro dissolution of D. cochinchinensis ultrafine powder were changed

which provided experimental foundation for the further study of D. cochinchinensis ultrafine powder.