This proposed trial is a multicenter,randomized and controlled clinical trial. The aim of this trial is to evaluate the efficacy and safety of acupuncture for treating pain of Endometriosis.The trial period will consist of three menstrual cycles of treatment, and three menstrual cycles in the follow-up period.We put forward the following hypothesis: the effect of acupuncture group is better than the control group on relieving pain.

Endometriosis is a kind of chronic gynaecology disease that endometrial tissue appear outside the uterine cavity , the main symptoms include dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility, etc. .The secondary progressive and aggravating dysmenorrhea is thought to be the most typical symptom of endometriosis.The epidemiology data shows that about 87.7% endometriosis patients accompany with dysmenorrhea, affecting majority of women's physical and mental health and quality of life seriously .The treatment for dysmenorrhea is still the key and pressing problem of endometriosis.Endometriotic lesions can be excised or ablated surgically, but the risk of recurrence is high. Drug therapy mainly involves the use of oral contraceptives, progesterone and androgen derivatives, gonadotropin-releasing hormone (GnRH) agonists and aromatase inhibitors, etc.,However, in some women the side effects may not be well tolerated or the pain relief provided may be inadequate. Therefore, a large number of patients with endometriosis are turning to complementary and alternative medicine such as acupuncture.Acupuncture, as an important component of traditional Chinese medicine is widely used in Asian countries,and it can treat different diseases, including endometriosis dysmenorrhea.The analgesia principle of acupuncture is based on the theory of holistic view of zang-fu organs and meridians.In traditional Chinese medicine, dysmenorrhea is etiologically caused by the stagnated blood or Qi circulation in the uterus. The pathological factors are mostly dampness, blood stasis,and Qi obstructions. Acupuncture stimulation, which involves thrusting or twisting needles,results in various biochemical reactions that can have effects throughout the body.When the running of blood and Qi is unobstructed, pain can be relieved.However, only some small trials considered to be lacking in quality or size to guide practice.So it is urgently necessary to design multicenter ,randomized controlled trial to prove it .

Inclusion criteria

1. Women age between 20 and 40.
2. Endometriosis diagnosed according to the Endometriosis Consensus Guidelines (Chinese Medical Association, 2015): 1) symptomatic endometriosis detected by laparoscopy or laparotomy; or 2) ovarian endometrioma detected by ultrasound or magnetic resonance imaging with pelvic pain.
3. Patients willing to receive acupuncture for pain relief.
4. Pelvic pain score equal or over 4 cm on the Visual Analogue Scale (VAS).
5. Regular menstrual cycle.
6. Signed informed consent

Exclusion criteria

1. Pelvic ultrasound demonstrates the endometrial cyst measures more than 5 cm in diameter and surgery is indicated.
2. Imaging examination suspects pelvic genital malignancies.
3. Cancer antigen-125 > 200 IU/L.
4. Pelvic infectious diseases.
5. Other severe disorders in heart, lung, liver, kidney, or mental disorders not able to cooperate in the study.
6. Patients who have received any other treatment for endometriosis that may affect the observation of the curative effects of acupuncture these three months.
7. Pregnancy or breastfeeding.
8. Refusal to be randomized.