长期以来，各种因素导致学者们对巴丹吉林沙漠确切范围的认识和理解存在争议，关于其面积大小属于中国第三大沙漠还是第二大沙漠存在颇多分歧。根据巴丹吉林沙漠相关领域研究新成果和2009年野外考察取得的相关数据资料，从地理学角度研究了确定巴丹吉林沙漠范围与界线的原则与涉及的问题，结合RS , GIS和GPS技术方法重新对巴丹吉林沙漠范围与界线位置进行了精确定位和定量分析。结果表明，巴丹吉林沙漠位于雅布赖盐湖与雅布赖山之西北，宗乃山、省道S218公路之西，黑河正义峡出山口、弱水东岸至古日乃湖之东，横跨5个经度，东西长约442 km;合黎山、北大山、黑山头之北，拐子湖、古居延泽之南，纵贯3个纬度，南北宽约354 km。地域范围位于39°04'15"N～42°12'23"N, 99°23'18"E～104°34'02"E，面积为5.2162万km²，应系我国仅次于塔克拉玛十沙漠的第二大沙漠。

The Badain Jaran Desert is a unique geomorphic unit with the world's highest sand hill and more than 100 lakes. However, there are different opinions on the boundary and the area of it, leading to the question whether its area is the second or the third in China. According to latest research achievements and extensive fieldwarks in 2009, questions related to the boundary and the area of the desert have been dealt with in the view of geography. By using the Landsat7-ETM+ images and GIS and GPS methods, the boundary of the Badain Jaran Desert was investigated and the area of it was reexamined. The results show that the Badain Jaran Desert starts from the southeastern edge of the Yabulai Salt Lake and Yabulai Mount and the eastern edge of the Zangnai Mount and S218 National Road, cannects with the western edge of the Zhengyi Valley on Heihe River, and reaches Ruashui River and Gurinai Lake. The north of it is the Guaizi Lake and the Ancient Juyan Lake. The south of it is the Heli Mount, Beida Mount and Heishan Mount. The Badain Jaran Desert crasses a langitude of 5 degrees with a length of 442 km from east to west, and a latitude of 3 degrees with a length of 354 km from south to north. It ranges from 39°04'15"N to 42°12'23"N and from 99°23‘18"E to 104°34'02"E, cavering an area of 52.162x10³ km². The Badain Jaran Desert cavers 7 caunties (banners or district)in 2 provinces. Therefore, it can be cincluded that the Badain Jaran is the second largest desert in China.