GB codes for the administrative regions of P. R. China are composed of six digits:

• The first two digits present provinces, autonomous regions, and municipalities directly under the Central Government (for example, 440000 for Guangdong Province; 150000 for the Tibet Autonomous Region; and 110000 fo r Beijing).

• The next two digits represent prefectures, prefecture-level cities, leagues, autonomous prefectures in each provinces and autonomous regions, and districts and counties in each municipality directly under the Central Government (for example, 440100 fo r Guangzhou City in Guangdong Province; 152200 for Xing'an League in the Tibet Autonomous Region; and 110100 for Shixiaqu in Beijing etc.). These digits are coded as:
  • 01-20, 51-70 for reprefecture-level cities;
  • 21-50 for prefectures including leagues and autonomous prefectures

• The last two digits represent counties including county-level Shixiaqu, county-level cities, counties, banners and autonomous counties (for example, 440182 for Huado City of Guangzhou City in Guangdong Province, 152224 for Tuquan County in Xing'an Le ague in the Tibet Autonomous Region, and 110108 for Haidian District of Beijing Shixiaqu). These digits are coded as:
  • 01-18 for county-level cities under the prefecture-level cities and Shixiaqu;
  • 21-80 for counties and banners;
  • 81-99 for county-level cities under the province