安史之乱以后,吐蕃乘势东进,不断攻占唐的大片领土,迫使唐廷不得不采取一系列措施来抵抗吐蕃的东扩,盐州城的修筑正是这一时代背景下的必然产物。本文依据有关材料分析了盐州城修筑的缘由、过程以及意义等。 After Anshun’s chaos, the Tubo throne moved eastward and constantly captured a large part of Tang’s territories, forcing that Tang Ting had to take a series of measures to resist the eastward expansion of Tubo. The construction of Yancheng was exactly the inevitable outcome of this era. Based on the related materials, this article analyzes the reason, process and significance of the construction of Yanzhou City.