Objective To evaluate the potential of chlorhexidine(Chx)-thermosensitive hydrogel as a local drug delivery system for periodontal treatment.Methods The release profiles of Chx from CS-HTCC/GP thermosensitive hydrogel in vitro were investigated.Moreover,the antibacterial activity of S-HTCC/GP-0.1%Chx thermosensitive hydrogel to oral representative pathogens - Porphyromonas gingivalis(P.gingivalis),Prevotella intermedia(P.intermedia) and Actinobacillus actinorn ycetemcornitans(A.actinom ycetemcomitans) was determined by inhibitory zone measurement.Results Chlorhexidine(Chx) released in vitro over 18 hours from the CS-HTCC/GP thermosensitive hydrogel in artificial saliva pH 6.8 which more effectively retarded the release of Chx.Three periodontal pathogens were susceptible to Chx thermosensitive hydrogel with the inhibitory zone diameters over the range of 12～14mm.Conclusion All results indicated that Chx thermosensitive hydrogel can be used as a local drug delivery system for periodontal treatment.