Objective To observe the effect of instant moxibustion on the levels of prostaglandin E_2（PGE_2）,prostaglandin F2α（PGE_（2α）） and arginine vasopressin（AVP） in the uterine tissues of dismenorrhea rats with cold-damp congealing and stagnation type and to explore its possible mechanism.Methods Female Wistar rats were randomly divided into blank group,model group,herble medicine group,pre-moxibustion group and instant moxibustion group,with 9 rats in each group.Cold-damp congealing and stagnation type primary dismenorrhea models were established by adopting（0±1）℃ ice waterextraction method combined with estradiol benzoate injection method.After modeling on the 8th day,in herble medicine group,Tongjingbao granules was given to the rats by intragastric administration.In pre-moxibustion group,mild moxibustion was carried out at ＂Shénquè＂（神阙 CV 8） and ＂Guānyuán＂（关元 CV 4） of the rats for 10 min at each acupoint.In instant moxibustion group,moxibustion as that in pre-moxibustion group was conducted for once after injection with oxytocin on the 11 th day.ELISA was adopted to detect the levels of PGE_2 and PGE_（2α） in the uterine tissues of rats,and radioimmunoassay was used for detection of AVP level in the uterine tissues of rats.Results Compared with the model group,the latent period of rats in herbal medicine group,premoxibustion group and instant moxibustion group obviously prolonged,the number of times of torsion reduced,and the total score of torsion decreased（P0.01）;compared with herbal medicine group,the latent period of rats in instant moxibustion group obviously prolonged,and the total score of torsion decreased（P0.05 or P0.01）;compared with pre-moxibustion group,the number of times of torsion of rats in instant moxibustion group reduced,and the total score of torsion decreased（P0.01）.Compared with blank group,the levels of PGE_（2α） and AVP and the ratio of PGE_（2α） and PGE_2 in the uterine tissues of rats in model group significantly i
