均田制自北魏太和九年至唐中叶,历时近三百年。在这近三百年中,均田制的基本精神和原则一直为历代所沿袭。然而在具体内容上,则不断地因时势变迁而有所损益,不断地发生着演变。均田制的变化,不惟发生于嬗递相交的各朝代,而且还发生于各朝之内。北魏、北齐、西魏北周、隋、唐都颁布均田令,又都不断地调整、补充和修订均田令。遗憾的是,各朝均田令修订的具体时间和内容,除唐代有较为详细的记载外,其余各朝皆无比较明确而翔实的记载。这给我们全面、系统、准确地研究均田制的发展演变带来了很大的困 Land system since the Northern Wei Dynasty Taihe nine years to mid-Tang Dynasty, which lasted nearly three hundred years. During these nearly three hundred years, the basic spirit and principle of the land leveling system have been followed by all generations. However, in terms of specific content, the profit and loss have been continually changed due to the change of the times and evolved continuously. The changes in the land-parity system occurred not only in the dynasties that crossed each other but also in the various dynasties. Northern Wei, Northern Qi Dynasty, Northern Wei Dynasty, Sui and Tang dynasties all promulgated the land orders, and they are constantly adjusting, supplementing and revising the land orders. Regrettably, the specific time and contents of the revision of the DPRK dynasties, except for the more detailed records in the Tang Dynasty, are not clearly and completely documented by the other dynasties. This has brought great difficulties to our comprehensive, systematic and accurate study of the development and evolution of the land leveling system