Abstract: Objective　To establish experimental periodontitis models in mandibular anterior teeth of beagle dogs, and to explore the influence of on immediately implants. Methods 　Six healthy adult beagle dogs were randomly divided into two groups：group A and group B. As a control group, dental plaque of group A was controled. Group B was experimental group. The silk ligatures would be forced into mandibular anterior teeth in order to establish periodontitis model. 4 weeks later, extract bilateral mandibular second premolar of all dogs at the same time, place implants immediately. Second surgery was performed 4 weeks after implants healing. Clinical and radiographic recording were repeated at 1,2,3,4,5,6,7and 8 weeks respectively after the abutments had been connected. Results　As time passed, observation results of implants 8 weeks later was: PPD（peri-implant probing pocket depth）in Group A(1.700±0.200)mm, Group B（5.083±0.133）mm; mSBI（modified sulcus bleeding index）in Group A（0.000±0.000）, Group B（2.830±0.408）; mPLI(modified plaque index) in Group A (0.170±0.408), Group B（2.830±0.408）, and PISF (peri-implant sulcular fluid) in Group A (0.752±0.043)mg, Group B（1.640±0.164）mg. Use independent sample t tests to compare the difference of the data, P<0.01, there was significant difference between two groups. The radiographc examination showed bone resorption to different degrees in Group B, and all the experimental implants in group B demonstrated significantly symptoms similar to human peri-implantitis. Conclusions　Experimental periodontitis modesl can be successfully established in beagle dogs. Periodontitis in mandibular anterior teeth of beagle dogs is similar to human periodontitis in mandibular anterior teeth. It can induce peri-implantitis of the distal implants naturally, and influence the incipient stability of early loading of immediate implants. The result of this experiment can provide some help for clinical research on immediate implants for periodontitis.