Objective To evaluate the analgesic effect of Erianin on bone cancer pain(BCP) model and its effect on spinal astrocytes activation and inflammatory response. Methods Fifty female Sprague Dawley (SD) rats were randomly divided into five groups (10 rats for each group): Sham operation group (group Sham), bone cancer pain group (group BCP), BCP+natural saline group (group BCP+NS), BCP+low-dose Erianin group (group BCP+Erianin(L)), BCP+high-dose Erianin group (group BCP+Erianin(H)). Walker 256 rat mammary gland carcinoma cells (about 4×104celIs) 10μL was injected into the right tibia to mimic the clinic pathological process of BCP. The corresponding drugs and NS were injected intraperitoneally once a day from 6 d to 21d after surgery. Paw withdraw thermal latency (PWTL) and paw mechanical withdrawal threshold (PMWT) were measured 1d before and 1, 3, 6, 9, 12, 15, 18 and 21d after surgery. The animals were sacrificed on 21d after surgery and the spinal cord were collected, immunofluorescence and western blot were used to detect changes in glial fibril1ary acidic protein (GFAP) protein, enzyme-linked immunosorbent assay(ELISA) was used to detect the changes of proinflammatory cytokine expression. Results Compared with group Sham, group BCP showed remarkable decreases in PMWT and PWTL at each time points (p0.05), and marked increases of spinal astroglia cells and tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 1β (IL-1β) expression in spinal cord (p0.05). Compared with group BCP+NS, groups BCP+Erianin(L) and BCP+Erianin(H) showed remarkable increases in PMWT and PWTL (p0.05), and marked decreases of spinal astrocyte and TNF-α, IL-6, IL-1β expression in spinal cord (p0.05). Conclusion Erianin can alleviate BCP in rats，and the mechanism may be related to inhibiting activation of spinal astrocytes and attenuating inflammatory responses.