Abstract: In order to study the antibacterial activity of Chinese medicinal herbs to Ureaplasma Urealyticum(Uu),we examined the inhibitory effect of 156 Chinese medicinal herbs to 14 standard strains of Uu by microdilution method in vitro.The results showed that Uu had a higher sensitivity to Cortex phellodendri,Radix angelicae dahuricae,Fructus kochiae,Radix et rhizoma rhei(MIC₉₀≤7.81mg of dried medicinal herbs/ml);a moderate sensitivity to Radix glycyrrrhizae,Radix isatidis,Rhizoma coptidis,Herba andrographitis,Herba houttuyniae(15.63≤MIC₉₀≤62.5);a lower sensitivity to Cortex meliae,Herba leonuri(62.590≤250);a certain sensitivity to Radix scutellariae,Herba ecliptae, Herba plantaginis at higher concentration(15.6≤MIC₉₀<250);not sensitive to other 141 Chinese medieinal herbs(MIC₉₀>250).It is our opinion that Chinese medicinal herbs are of momentous signficance in the treatment of Uu infection.

Key words: Ureaplasma Urealyticum, Microdilution method, MIC