Approximately 50-70% of patients experience incision-induced mechanical nociception after sur-gery. However, the mechanism underlying incision-induced mechanical nociception is stil unclear. Interleukin-10 and brain-derived neurotrophic factor are important pain mediators, but whether in-terleukin-10 and brain-derived neurotrophic factor are involved in incision-induced mechanical no-ciception remains uncertain. In this study, forty rats were divided randomly into the incision surgery (n=32) and sham surgery (n=8) groups. Plantar incision on the central part of left hind paw was performed under anesthesia in rats from the surgery group. Rats in the sham surgery group re-ceived anesthesia, but not an incision. Von Frey test results showed that, compared with the sham surgery group, incision surgery decreased the withdrawal threshold of rats at 0.5, 3, 6 and 24 hours after incision. Immunofluorescence staining in the dorsal root ganglia of the spinal cord (L 3-5 ) showed that interleukin-10 and brain-derived neurotrophic factor were expressed mainly on smal-and medium-sized neurons (diameter<20μm and 20-40μm) and satel ite cells in the dorsal root ganglia of the spinal cord (L 3-5 ) in the sham surgery group. By contrast, in the surgery group, high expression of interleukin-10 and brain-derived neurotrophic factor appeared in large-sized neurons (diameter>40μm) at 6 and 24 hours after incision surgery, which corresponded to the decreased mechanical withdrawal threshold of rats in the surgery group. These experimental findings suggest that expression patt shift of interleukin-10 and brain-derived neurotrophic factor induced by inci-sion surgery in dorsal root ganglia of rats was closely involved in lowering the threshold to me-chanical stimulus in the hind paw fol owing incision surgery. Pain-related mediators induced by in-cision surgery in dorsal root ganglia of rats possibly underlie mechanical nociception in ipsilateral hind paws.