華北在東漢末年至五胡期間陷入長期的爭戰局面，先前和平時期的聚落體系瓦解，此時期戰時聚落成為普遍現象，也是漢型聚落過渡到隋唐型聚落的重要轉型期稱為「塢壁別的戰時聚落，在西晉永嘉之亂以後是頗為普遍，但在三國以前，「塢壁」不應泛指一般的宗鄉部曲的武裝聚落，為延續東漢以來，屬官方性質的山地防戍體系的一環。「塢」原來是漢羌邊區的軍事占候設施，由於羌患逐次內地化，「塢壁」也逐漸於內地設立，到了漢末其分布已集中在京師洛陽的近畿山區。塢壁的分布環境是山區的通谷，要道，為重要的戰略區位。 至於民間的戰時聚落，所選的位置多避開兵家常爭的戰略區位。避入山區者，多尋深險山區以避世；至於留在平原者，則多遠避有寇患的山麓地帶，往平原內部集中，其聚落規模也由於吸附外來人口而擴大。這些民間聚落是不選在要道、通谷的，在區位與環境選擇上，與帶有官方性質的「塢壁」有明顯的差異。

　　　　　The system of peacetime settlements were crumbled and the wartime settlements became popular after the Dong-Wan Dynasty (A.D.190) due to long-dragging wars. This was an important transformed into the Tan'g style. Wul walls, one form of wartime settlements, was officially disposed by the Dong-Hah regime as part of their defensive system in mountainous areas. In the late Dong-Hen, the invaders, Chiang race, gradually expended their territories and intruded the mearby region of the capital. Experiencing the threaten of Chiang race, the Dong-Hah government started to establish Wul walls in the mountainous areas around the capital. In general, Wul walls were distributed in the .strategic areas such as the major traffic points which connected valleys and main passages. On the contrary, the location of civilian settlements ,ere chosen in some different positions to avoid strategic location. City wails located in great plains in order to escape the threaten of wars. The differences between official defensive system, wul walls, and civilian settlements in that the latter one hardly select any major traffic points.