Abstract: According to the archeological digging and historical record of Erlitou, in this historical stage, not only the classes and class struggle exist hut also countries appear.

• 文章摘要: 二里头文化的考古发掘和文献记载表明，在这个历史阶段，不仅存在着阶级和阶级斗争，而且已经出现了国家。