Dulan County (Mongolian: ᠳᠤᠯᠠᠭᠠᠨ ᠰᠢᠶᠠᠨ; Tibetan: ཏུའུ་ལན་རྫོང་; Chinese: 都兰县) is a county of east-central Qinghai province, China. It is under the administration of Haixi Mongol and Tibetan Autonomous Prefecture.

With an elevation of around 3,200 metres (10,000 ft), Dulan County has a cool semi-arid climate (Köppen BSk) that grades into a cool arid climate (BWk) north of the mountains. Winters are long, frigid and extremely dry whilst summers are warm in the south and very warm in the less elevated north. Average low temperatures are below freezing from early/mid October to mid/late April; however, due to the wide diurnal temperature variation, only December and January have an average high below freezing. With monthly percent possible sunshine ranging from 60% in July to 81% in November, the county seat is very sunny, receiving 3,092 hours of bright sunshine annually; relative humidity in all months is below 50% and for seven months is below 40%. The monthly 24-hour average temperature ranges from −9.6 °C (14.7 °F) in January to 15.2 °C (59.4 °F) in July, while the annual mean is 3.7 °C (38.7 °F). Over 70% of the annual precipitation of 229 millimetres or 9.02 inches is delivered from May to August.

Dulan County is divided into 4 towns and 4 townships.