The key cultural relics protection unit of the country belongs to the Neolithic ruins, which have a history of six or seven thousand years. It consists of 39 sites and relics, distributed on sand dunes in the middle and lower reaches of the Nenjiang River, accompanied by depressions, marshes and lakes. These sites leave rich relics and relics, which provide an important basis for studying the national culture of fishing and hunting in the grasslands of northern China.