OBJECTIVE： To study the role of glucagon-like peptide 1 receptor （GLP-1R） on chronic inflammatory pain mechanism in rats. METHODS： The rats were randomly divided into normal control group， normal saline group 1 and complete Freund’s adjuvant （CFA） group 1. Other rats were randomly divided into normal saline group 2， CFA 2 group and （GLP-1R agonist） GLP-1 group （5 μg/kg）. Chronic inflammatory pain model was induced by left hind toe side injection of CFA. The latter 3 groups were given relevant medicine intraperitoneally on the 7th day after modeling， for consecutive a week. The licking incubation of the former 3 groups were determined by Hargreaves thermal pain instrument 1 d before modeling （－1 d）， on modeling day （0 d）， 1， 3， 7， 14 d after modeling； the licking incubation of the latter 3 groups were determined 8， 10， 12， 14 d after modeling； those of each 6 rats were determined at each time point. 7 d after modeling， distribution of receptor GLP-1R molecule in model group was observed by immunofluorescence double labeling. Western blot method was used to detect the expression of GLP-1R protein in dorsal root ganglia （DRG） of rats in former 3 groups 1， 3， 7 and 14 d after modeling. The expression of GLP-1R， TNF-α， IL-6 and IL-1β protein in DRG of rats were also determined in latter 3 groups 14 d after modeling； those of each 3 rats were determined at each time point. RESULTS： Compared with normal control group and normal saline group 1， licking incubation of CFA group 1 was shortened significantly 1， 3， 7， 14 d after modeling （P＜0.01）， and the protein expression of GLP-1R in DRG was decreased significantly （P＜0.01）； there was no statistical significance in licking incubation －1 and 0 d （P＞0.05）. GLP-1R molecules were double labeled with NeuN and calcitonin gene-related peptide （CGRP）-positive neurons no significant double marker was found between GLP-1R molecules and phytohemagglutinin B4 positive neurons. Compared with normal saline group 2， licking incubation of CFA group 2 was shortened significantly 8， 10， 12， 14 d after modeling （P＜0.01）； the protein expression of GLP-1R in RG was decreased significantly 14 d after modeling （P＜0.01）； the protein expression of TNF-α， IL-6 and IL-1β were increased significantly （P＜0.01）. Compared with CFA group 2， licking incubation of GLP-1 group was prolonged significantly 8， 10， 12， 14 d after modeling （P＜0.05 or P＜0.01）； the protein expression of GLP-1R in DRG was increased significantly 14 d after modeling （P＜0.01）， and the protein expression of TNF-α， IL-6 and IL-1β were decreased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： GLP-1R molecule is mainly expressed in CGRP-positive neurons of DRG. The expression level of GLP-1 receptor gradually decreases with the occurrence and development of chronic pain. The increase of GLP-1R expression can effectively relieve chronic inflammatory pain， which is related with reducing reduce the expression of inflammatory factors in DRG.