Deqi, according to traditional Chinese medicine, is a specific needle sensation during the retention of needles at certain acupoints and is considered to be necessary to produce therapeutic effects from acupuncture. Although some modern researches have showed that Deqi is essential for producing acupuncture analgesia and anesthesia, the data are not enough. It is a paper of a multicenter, randomized controlled study protocol, to evaluate the influences of Deqi on acupuncture SP6 in Cold and Dampness Stagnation pattern primary dysmenorrhea patients, in terms of reducing pain and anxiety, and to find out the relationship between Deqi and the temperature changes at SP6 (Sanyinjiao) and CV4 (Guanyuan). The results of this trial will be helpful to explain the role of Deqi in acupuncture analgesia and may provide a new objective index for measuring Deqi in the future study. This trial is registered with ChiCTR-TRC-13003086.