Gate building, was built in the city on the city front doorway floor, because it controls into the city must pass through the protective moat "gate" bridge named. And said gate building towers, because soldiers stationed inside the building, the placement of firearms artillery to fire into the city channel blockade, destroy the enemy attack the gates, hence the name. Ming and Qing Dynasties on a four city gates were built on the city gate building, because of the early Republic to build bridges in the city outside the moat in order to facilitate traffic, while the gate building on the city and the demolition of all. Now an S. gates of the old building by the Ming rehabilitation.

- Xi'an city wall gate building -

East Gate gate building, the city of the Ming and Qing Changle Gate Xi'an month gate building. Late Ming. On the city walls located on the front of the doorway to build from brick through. Gate building three wide, high floor, roof overhang mountain form, the front wall and floor walls became one month, and the open arrow window two layers, each layer of tin; open arrow windows on both sides of each gable two rows, each row two holes, together twenty holes. Pro front gate guard moat, drawbridge in charge of protecting the ups and downs on the moat, the guardian of the channel into the city, to the gates of important buildings in the defense system. Usually when pedestrians, gate upstairs soldier namely put off the drawbridge; in case of an alarm, the soldiers will pull up the drawbridge and keep building to break their way, so that the enemy can not cross the moat guard into the city; when the enemy attacked, artillery Arrow virtue of gate building arrow shooting, sniping enemy soldiers, into the city in order to maintain this channel yet. East Gate on the city gate building in the early Republic due to bridge on the moat and removed.

- Xi'an city wall south gate gate building -

South Gate, Simon and north gates floor with architectural form to the East Gate gate building, but South Gate gate building destroyed in the war at the time Chongzhen sixteen years (1643) October Li Zicheng peasant army to attack the city of Xi'an, after the Qing Shunzhi thirteen three years (1656) Ming Chen pole in accordance with the new system rebuilt by the governor of Shaanxi. South Gate gate building with Simon after reconstruction, North Building gates early Republican removed.

1989 South Gate gate building was rebuilt in accordance with the prescribed system. The new South Gate gate building, located on the city above the doorway, floor brick through the body to build from. Three wide, high floor, roof hanging-hill. Arrow windows open front two rows, each row of six holes; each side gable windows open arrow two rows, each row two holes twenty-hole co-arrow windows. Wooden inner upper open twelve, each intermediate gating, the opening and the left and right sides of five wooden windows.