To investigate the effect of mild moxibustion on uterine microcirculation in the rat model of primary dysmenorrhea(PD).Methods:Forty female SD rats were randomized into blank，blank+moxibustion，model，and model+moxibustion groups.The rat model of PD was prepared by estradiol benzoate combined with oxytocin.The mild moxibustion was performed at Guanyuan(CV4) and Sanyinjiao(SP6).The writhing response，uterine histomorphology，uterine microvascular diameter，and hemorheology were observed and measured respectively.Results:Except the blank group and blank+moxibustion group，the model group and model+moxibustion group showed writhing response，indicating that the PD model was successfully established.Compared with the blank group and blank+moxibustion group，the model group showed increased transverse diameter of uterus(P<0.05) and decreased microvascular diameter(P<0.05).Compared with the model group，the model+moxibustion group showed decreased transverse diameter of uterus(P<0.05) and increased microvascular diameter(P<0.05).Compared with the blank group，the model group and model+moxibustion group showed decreased whole blood viscosity at different shear rates，erythrocyte rigidity index，erythrocyte deformability index，K value of erythrocyte sedimentation equation，and hematocrit(P<0.05).Compared with the model group，the model+moxibustion group showed increased whole blood viscosity at different shear rates，erythrocyte rigidity index，erythrocyte deformability index，K value of erythrocyte sedimentation equation，and hematocrit(P>0.05).There were no significant differences in the indexes between the blank group and blank+moxibustion group(P>0.05).Conclusion:Mild moxibustion can inhibit dysmenorrhea induced by oxytocin in rats by alleviating uterine edema，improving uterine hemorheology，and alleviating uterine microcirculation disorder.