Abstract: This paper investigates the construction of military cities and their defensive systems as documented in the Wujing Zongyao, focusing on the types, structural designs, spatial deployments, and distinctive features of defensive architecture during mid-Northern Song dynasty. By comparing these military cities with those of other historical periods, it highlights their transitional characteristics amid the shift from cold-weapon to hot-weapon warfare. The findings provide valuable insights into the evolution of military urbanism, enriching scholarly understanding of fortification strategies during the Northern and Southern Song dynasties.