Objective: To study the influence of differenet pH on the oil-water partition co-efficient

transdermal absorption characteristics and the anti-inflammation effect of brucine solution. Method: The oil-water partition co-efficients and the permeation rates of brucine in pH 5

7.4 and 9 phosphate buffer solution(PBS) were measured; The effects of brucine in pH5

7.4 and pH 9 on the inflammatory edema of ear induced by xylol in mice were also determined. Result: The oil-water partition coefficient and permeation rate of brucine in pH 9 were(22.17±0.4) and (2.84±0.10)μg ·cm-2 ·h-1

which was almost 239.5 times and 3.15 times more than the corresponding data obtained under pH 5 PBS. The effect of inhibiting the inflammatory edema in the ear of mice induced by xylol was also markly increased under pH 9. Conclusion: The oil-water partition coefficient and transdermal absorption characteristics of brucine can be improved by increasing pH. which also markly promotes the anti-inflammatory activities of brucine.