Objective: To compare the powder properties between common powder and micropowders of Angelica to provide experimental evidence for the superfine grinding application. Method: Morphology structure

hygroscopic property

liquidity

surface area and porosity of Angelica powders were investigated; the contents and the dissolution of ferulic acid of Angelica powders were determined by HPLC. Result : With the decreasing of particle size of powders

the surface area

pore volume and moisture increased

and the liquidity decreased; the contents of ferulic acid from four Angelica powders were in the order of: common powder > ultrafine powder I > ultrafine powder II > ultrafine powder III; but with the crushing level increased

dissolution rate and the total dissolution of the ultrafine powder II was higher than levels of particle size in other angelica powder. Conclusion : An appropriate degree of micronization is helpful for the dissolution of the active components in Angelica.