The west-east ranges

consist mainly of three groups: The northern group includes the Tianshan range which crosses central Xinjiang, and the Yinshan range which extends across the middle groups includes the Kunlun range straddling the Xinjiang-Tibet border, and the Qinling range, cutting across the central part of the country; and the southern group consists of the Nanling mountains on the Human-Jiangxi-Guangdong-Guangxi border.

The Himalayas generally run in a west-east direction. The west-east ranges are important geographical boundaries in China. The Tianshan Mountains divide Xinjiang into southern and northern parts; the Yinshan mountains are part of the boundary line between the interior and boundary line between the first and second steps of the staircase in china's topographical outline; the qinling Mountains are the watershed of the changjiang and Huanghe river systems and the geographical dividing line between northern and southern china; and the Nanlinf Mountains are the watershed of the changjing zhujiang rivers and a natural geographical divide in southern China.