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Paleomagnetic study on the Cenozoic volcanic rocks from the Tuoyun Basin of the southwest Tien Shan indicates that most samples could isolate a stable characteristic remanent magnetization with reversed polarity. The positive fold test suggests that the characteristic component is very likely to be a primary magnetization acquired in the formation of rocks. Comparison with the reference Eurasia poles at 60 Ma indicates little or insignificant N-S convergence between the south edge of southwest Tien Shan and Siberia since the onset of the India/Asia collision at the Eocene. Furthermore, the Cretaceous and Tertiary paleomagnetic results suggest that the Tuoyun Basin was subjected to a local clockwise rotation of 20 . -35 . With respect to Eurasia since the Paleocene time, which is probably subsequent to the Cenozoic northward compression of the Pamir arc.