Abstract: In order to investigate the effects of four Tibetan medicine extracts on the biofilm and spore formation of Clostridium perfringens, in the test, the silver staining method was used to identify the biofilm of Clostridium perfringens strain Nyingchi-C20, the crystal violet method was used to detect the biofilm forming ability, and the minimum inhibitory concentration（MIC） of four Tibetan medicine extracts was detected by micro broth dilution method. The extracts of Tibetan medicines with good antibacterial effect were diluted and divided into 6 groups, which were liquid thioglycolate medium（TSB） group, 1/8 MIC group, 1/4 MIC group, 1/2 MIC group, MIC group and antibiotic vancomycin MIC（VAN） group, respectively. After each group was inoculated with 300 μL of bacterial suspension, the drug solution of each group was added to 30 mL. After incubation, the biofilm suspensions of each group were taken to detect their effect on the expression of genes related to biofilm formation and spore formation by real-time fluorescence quantitative PCR. The results showed that the minimum inhibitory concentrations of Aristolochia methanolic extract and 75% ethanol extracts of Terminalia, Herpetospermum seed, and Amomum were 0.2 mg/mL, 0.8 mg/mL, 0.4 mg/mL, and 1.6 mg/mL, respectively. Compared with the TSB group, the expression levels of agrB gene and htrA gene（except for the 1/8 MIC group and 1/4 MIC group） in each MIC group of Aristolochia methanol extract were significantly or extremely significantly lower（P＜0.05 or P＜0.01）, and the expression levels of sigK gene in the 1/2 MIC group and MIC group were significantly or extremely significantly higher（P＜0.05 or P＜0.01）. The expression levels of agrB, htrA, abrB, ribD, codY, and spo0A genes were significantly or extremely significantly reduced in the 1/8 MIC group（except ribD, codY, and spo0A genes）, the 1/4 MIC group（except ribD gene）, the 1/2 MIC group, and the MIC group of Terminalia 75% ethanol extract（P＜0.05 or P＜0.01）. The relative expression levels of agrB gene in the 1/4 MIC group, 1/2 MIC group and MIC group of 75% ethanol extract of Herpetospermum seed were extremely significantly reduced（P＜0.01）, and the relative expression levels of minD gene in the 1/8 MIC group, 1/4 MIC group, 1/2 MIC group and MIC group were significantly and extremely elevated（P＜0.01）. The relative expression levels of argG and ribD genes in the 1/2 MIC group and argG, ribD and ribE genes in the MIC group were significantly or extremely elevated in the 75% ethanol extract of Amomum（P＜0.05 or P＜0.01）. The results indicated that the four Tibetan medicine extracts had certain inhibitory effects on Nyingchi-C20 strain, and had different degrees of effects on the expression of genes related to its biofilm and spore formation.