This is a prospect, randomized control trial to evaluate merits between flip and no flip technique in Shang Ring children circumcision.

The boys between 7 and 12 years old seeking for circumcision in The Affiliated Hospital of Medicine School of Ningbo University will be evaluated. Those who match the inclusion criteria and without exclusion criteria will be recruited.

The investigators will perform randomization preoperatively. participants were distributed into No Flip Group and Flip Group correspondingly according to a table of random number.

All of the procedures will be performed by a specific study surgeon in the hospital operation room. An assistant will take the pictures and recorder the parameters needed. In both groups, participants will be measured twice by a scale plate of holes, the diameter of penis with the foreskin noneverted and the diameter of exposed glans. Local anesthesia will be administered to the dorsal penile nerve using 2% lidocaine. The operation will not begin until the anesthesia is satisfied. The proper ring will be chosen according to different strategies of two groups. Participants will stay in hospital for 24 hours after operation. Pain during operation, half a hour post-operation and 24 hours will be evaluated, adverse events at hospital will be recorded carefully as well.

Participants will be advised to return usually at 7th, 14th, 21st, 28th and 90th post-operative days. However, if the wound does not heal completely 28 days post-operatively, the participant will be asked come to visit weekly until complete healing. All of the assessments will be performed and recorded by the lead investigator.

Inclusion Criteria:

• Aged between 7 years and 12 years(inclusive);
• Must be accompanied by the parent or legally acceptable representative (LAR), who freely agrees with participation of the child into the study;
• Must tolerate local anesthesia;
• Must be in good general health;
• Parent or LAR and if possible the client must be able to understand study procedures and requirements of study participation;
• Parent or LAR must agree to return the client to the study site for the full schedule of follow-up visits after his circumcision;
• Parent or LAR must agree the study staff to take photos during operation or follow-up if necessary, and
• Parent or LAR must agree to provide the study staff with an address, phone number, or other locator information

Exclusion Criteria:

• Has a known allergy or sensitivity to lidocaine or other local anesthesia;
• Takes a medication that would be a contraindication for elective surgery (e.g anticoagulant , steroid);
• Has known bleeding/clotting disorder (e.g. hemophilia);
• Has an active genital infection, anatomic abnormality or other condition(e.g. concealed penis, hypospadias, epispadia, micropenis);
• Is currently participating in another biomedical research study; or
• Participants under other condition (e.g. severe obesity, diabetes or sickle cell anemia) should be excluded from this study in the opinion of the surgeon.