Objective: To explore the best ratio of Danggui Buxue Tang for whitening efficacy by investigating whitening efficacy caused by different proportion of Astragali Radix and Angelicae Sinensis Radix in this compound. Method: Biochemical-enzymic method was adopted to measure tyrosinase inhibition rate of Danggui Buxue Tang and 1

1-diphenyl-2-picrylhydrazyl(DPPH) method was adopted to measure its antioxidant activity.Franz diffusion cell test was used to evaluate skin permeation of Danggui Buxue Tang. Result: Optimum proportion of Astragali Radix and Angelicae Sinensis Radix in this compound was 1 : 7.Under this proportion

its inhibition rate of tyrosinase achieved 89.65% and scavenging ratio of DPPH free radicals achieved 90.96%.Accumulative permeation amounts in 24 h of ferulic acid and calycosin-7-O-β-D-glucoside were 0.030 4

0.001 2 mg · cm-2

permeabilities were 59.27% and 57.79%

respectively. Conclusion: Change of compatibility ratio can affect efficacy of Danggui Buxue Tang

or even change status of compatibility between monarch and ministerial drug

then it may change syndrome and function of this prescription.