The postcode of Bailong Building, Huangsi Street, Chaoyang District, Beijing is 100 120. Beijing Bairun Fitness Bailong Club is a fitness center, located at Floor B 1 of Bailong Building, Huangsi Street 15, Chaoyang District, Beijing, with zip code 100020. PostalCode (English: postal code, also known as postal code) is a coding method for a country or region to divide the whole country in order to realize the automation of mail sorting and the digitalization of postal network, and to speed up the delivery of mail.