Objective: To screen technological conditions of lactose micropowder grinding modification to decrease hygroscopicity of Angelicae Dahuricae Radix(ADR) extract and analyze anti-absorption mechanism of lactose micropowder. Method: With moisture absorption rate as index

single factor test was adopted to investigate effects of kinds of lactose micropowder

ratio of raw materials to accessories and grinding time on technological conditions of lactose micropowder grinding modification

modifiers were supported by physical indexes

such as particle size distribution

microstructure and so on. Result: Optimal technological conditions of lactose micropowder grinding modification to decrease hygroscopicity of ADR extract were as follows:ARD extract-lactose micropowder(crushed 1 min) of 1:1

grinding time of three minutes.Particle sizes d0.1

d0.5 and d0.9 of modifier were 3.477

15.078

54.501 μm

respectively.The contact angle was (7.7±0.66) °

surface of ARD extract was coated by lactose micropowder particles. Conclusion: Available micronizing lactose can significantly decrease absolute values of initial velocity and acceleration of moisture absorption of ADR extract for reducing its hygroscopicity.Possibility of anti-absorption effects is that lactose particles are attached to surface of ADR extract after grinding modification.