Nine sheep were randomly divided into blank group， control group， and model group （n=3）.The sheep in blank group were not treated； the right maxillary bicuspid teeth of the sheep in control group and model group were removed， and the sheep received immediate implantation. After three months，when the implant bone bonding formed，the implant neck of the sheep in model group were ligated by the No.6 silk loop. The sheep in blank group were sacrificed at day 0，the sheep in control group were sacrificed after 3 months， and the sheep in model group were sacrificed 4 weeks after the ligation of No.6 silk loop. The gingival crevicular fluid was obtained before sacrifice and the gingival tissue samples were obtained after sacrifice.The morphology of gingival tissue of the sheep in control group and model group was observed.The gingival index（GI），attachment loss （AL），and periimplant pocket（PD） deep of the sheep in control group and model group were detected.The bone densities around the implants of the sheep in various groups were observed by special X-ray machine. The levels of IL-17 and IL-23 in gingival crevicular fluid of the sheep in various groups were determined by ELISA method，the expression amount of IL-1α mRNA in gingival tissue of the sheep in various groups were determined by Real-time fluorecence quantificative PCR（RT-qPCR） method，and the expression amounts of COX-2 protein in gingival crevicular fluid of the sheep in various groups were determined by Western blotting method.

The morphology observation results showed that the gingival tissue around implants of the sheep in model group presented redness and swelling and bleeding on probing， and the texture became soft with exudation.Compared with control group，the PD and AL of the sheep in model group were increased（P<0.05），while there were no significant inflammation of the sheep in blank group and control group. The X-ray detection results showed that the shadow around of implant of the sheep in model group was found， but it was not found in control group.Compared with blank group， the levels of IL-23 in gingival crevicular fluid of the sheep in control group and model group were significantly increased（P<0.05）. Compared with blank group and control group， the level of IL-17 in gingival crevicular fluid of the sheep in model group was significantly increased（P<0.05）. Compared with blank group and control group， the expression amounts of IL-1α mRNA and COX-2 protein in gingival tissue of the sheep in model group were significantly increased.

The peri-implantitis sheep models are successfully established by using the silk loop ligation. The high expression of inflammatory factors in gingival crevicular fluid and gingival tissue of the model sheep indicates that the inflammatory factors may play a certain role in promoting the development of peri-implantitis.