Abstract: Objective To observe the expression of basic fibroblast growth factor-2 (FGF-2) and its receptors in the anterior cingulate cortex (ACC) of the rat with chronic inflammatory pain. Methods Complete Freund’s adjuvant (CFA) was injected into the rat’s unilateral hind paw to induce chronic inflammatory pain. The bilateral ACC was harvested at 4 different time points after CFA injection (EM>n/EM> =3， for each time point). RT-PCR and Western blotting were used to examine the mRNA and protein expression of FGF-2 and its receptors, respectively.Results Unilateral paw injection of CFA induced pain hypersensitivity. After CFA injection, the expression of FGF-2 and FGFR1 mRNA increased at the 6th hour, 3rd day, 7th day, 14th day in the ipsilateral and contralateral ACC. FGFR2 mRNA increased at the 3rd day, 7th day and 14th day in the ipsilateral ACC. The FGF-2 protein also increased in bilateral ACC at the 6th hour, 3rd day and 7th day. Conclusion FGF-2 may be involved in the processing of pain through FGFR1 in

Key words: Complete Freund’s adjuvant, Basic fibroblast growth factor, Inflammatory pain, Anterior cingulate cortex, RT-PCR, Western blotting, Rat