Codes | Names | | Codes | Names |
IA | Wanda Mt and Sanjiang Plain low mountains and hills sub-region | | IA1 | Sanjiang alluvial plains small-region |
| IA2 | Wanda Mt low mountains and hills small-region |
| IA3 | Xingkai Lake alluvial-lacustrine plains small-region |
IB | Changbai Mt middle and low mountains, platforms and hills sub-region | | IB1 | Changbai Mt middle and low mountains, lava platforms small-region |
| IB2 | Eastern Liaoning low mountains and hills small-region |
| IB3 | Zhangguangcai Mt middle and low mountains and hills small-region |
IC | Eastern Shandong low mountains, hills and plains sub-region | | IC1 | Jiaodong low mountains and hills small-region |
| IC2 | Jiaolai alluvial plains small-region |
| IC3 | Central Shandong middle and low mountains and hills small-region |
ID | Xiao Hinggan Mt low mountains, hills and platforms sub-region | | ID1 | Eastern Xiao Hinggan Mt low mountains and hills small-region |
| ID2 | Western Xiao Hinggan Mt hills and lava platforms small-region |
IE | Songhua River-Liaohe River Plains sub-region | | IE1 | Xiao Hinggan and Dahei Mts piedmont alluvial-diluvial plains and platforms small-region |
| IE2 | Lower reaches of Liaohe River alluvial-marine plains small-region |
| IE3 | Songhua River-Nenjiang River alluvial-lacustrine plains small-region |
| IE4 | Upper reaches of Liaohe River diluvial-alluvial plains small-region |
| IE5 | Eastern foot of Da Hinggan Mts hills small-region |
| IE6 | Middle reaches of Liaohe River alluvial plains small-region |
Second-order sub-regions | Third-order small-regions |
Codes | Names | Codes | Names |
IF | Yanshan Mts & western Liaoning low mountains, hills and platforms sub-region | IF1 | Western Liaoning hills and platforms small-region |
IF2 | Yanshan Mt low mountains and hills small-region |
IG | Northern and Eastern China plains sub-region | IG1 | Bohai Sea marine plains small-region |
IG2 | Northern Jiangsu lacustrine-marine plains small-region |
IG3 | Jiangsu and Zhejiang alluvial delta plains small-region |
IG4 | Huang-Huai-Hai alluvial plain small-region |
IG5 | Piedmont of Taihang Mts diluvial-alluvial plains small-region |
IG6 | Piedmont of Funiu and Dabie Mts alluvial-diluvial plains small- region |
IH | Ningzhen plains, hills and mounds sub-region | IH1 | Chuzhou low mountains, hills, mounds and plains small-region |
IH2 | Southern Yangtze River hills and plains small-region |
IH3 | Nanjing lower reaches of Yangtze River Plains small-region |