This data is derived from the National Basic Geographic Information Resources Catalogue Service System, which provides 11 million national basic geographic databases free of charge by the National Basic Geographic Information Center in November 2017. We have spliced and cut the source of the three rivers as a whole, so as to facilitate the use of the study of the source area of the three rivers. This data set is composed of 1:1 million administrative boundary layers (BOUA) and administrative boundary line layers (BOUL) in Sanjiangyuan area. Names and definitions of BOUA attribute items: Attribute Item Description Fill in Example PAC Administrative Division Code 513230 NAME Name Rangtang County Names and definitions of BOUL attribute items: Attribute Item Description Fill in Example GB National Standard Classification Code 630200 The meaning of BOUL attribute items: Attribute Item Code Description GB 630200 Provincial Boundary GB 640200 District, Municipal and State Administrative Region GB 650201 County administrative boundaries (determined)