In order to determine the process and characteristics of channel geometry adjustments of the Tarim River, the morphological evolution features and influencing factors were analyzed based on the measured flow and sediment data as well as the mainstream cross-sectional profiles from 2005 to 2013. The results show that the channel geometry in the middle and upper reaches shrank gradually from 2005 to 2009, with a decreasing trend of the bankfull area. The fluvial erosion intensity during flood seasons was enhanced from 2010 to 2013, resulting in a lateral adjustment for the bankfull channel geometry in the braided reach characterized with wider and shallower cross-sections. The adjustment of the transition reach was relatively stable. Variation trend of the fluvial erosion intensity during flood seasons in the meandering reach was similar to that in the braided reach, and the cross-sections developed to be narrower and deeper with slight bankfull width variation. From 2009 to 2011, the longitudinal channel slope in the braided reach and the transition reach decreased by 1. 7% and 3. 0%, respectively, resulting in a flat river bed slope. However, it increased by 1. 6% in the meandering reach with little fluvial erosion. Fluvial erosion intensity can better respond to the channel geometry variation, which can be used to predict erosion and deposition of the bankfull channel. In addition, the stability of the river bank soil is poor and the river bank can be easily decomposed by the action of the near shore water flow, which accelerates the adjustment process to some extent.