OBJECTIVE:To study the effect of natural emulsifier acacia senegal on in vivo and in vitro performance of chloro-genic acid self-microemulsion. METHODS:Chlorogenic acid self-microemulsion containing acacia senegal(new chlorogenic acid self-microemulsion)was prepared by using acacia senegal to gradually replace polysorbate 80 in chlorogenic acid self-microemul-sion containing nonionic emulsifier (traditional chlorogenic acid self-microemulsion). The appearance,morphology,particle size,conductivity,pH value,stability,in vitro release and intestinal absorption kinetics of the 2 kinds self-microemulsions were evaluated. RESULTS:50％of polysorbate 80 was replaced by acacia senegal in new chlorogenic acid self-microemulsion. The tradi-tional and new chlorogenic acid self-microemulsions had clear appearance,and approximately spherical drops. Particle sizes were (24.53 ± 3.03),(35.51 ± 5.91) nm;dectrical conductivities were (195.6 ± 0.3),(189.5 ± 0.4)μs/cm;and pH were 3.87 ± 0.02, 4.08 ± 0.03 (n=3),respectively. Compared with traditional chlorogenic acid self-microemulsion,the absorption rate constant,ef-fective permeability coefficient and absorption amount of the new one in duodenum,jejunum,ileum were increased a little (P>0.05);the above indexes in colon were obviously decreased (P<0.05). CONCLUSIONS:The new chlorogenic acid self-micro-emulsion can maintain the performance of traditional one,and increase absorption of chlorogenic acid in small intestine.