Based on high-resolution GPS measurements on the Koxkar Glacier in the Tianshan Mountains, the spatial-temporal variations of flow velocity on the glacier were analyzed. The fastest flow was found near the equilibrium line (4 000~4 200 m a.s.l.), of which the horizontal flow velocity reached 86.69 m·a~(-1) and the vertical flow velocity reached 15.34 m·a~(-1). In the lower part of the glacier, where the extensive debris cover developed, ice flow was slower, with horizontal ice velocity varying between 0~5 m·a~(-1), and vertical ice velocity varying between 0~2 m·a~(-1), due to reduction in supply of ice mass and influence of thick debris cover. The variation of flow velocity with elevation met the general glacier flow law, but due to the influence of terrain, occasionally there was some spatial fluctuation in vertical flow velocity. Analysis of the seasonal variation of flow velocity reveals a good relationship between ice flow and climate factors, which may reflect the response of glacier flow to fast climate change.