We report paleomagnetic results for Early-Middle Ordovician limestone rocks from the eastern part of the Hexi Corridor, northwest China. The characteristic high temperature component B isolated from 74 out of 114 samples exhibited dual polarity and passed the fold and reversal tests at the 95% confidence level. The corresponding paleopole, at 326.5 ¿E, 31.8 ¿N with A95=9.5¿, is in agreement with the coeval poles from the stable North China Block (NCB). It implies that the Alashan/Hexi Corridor (AHC) terrane was part of the NCB since the Early-Middle Ordovician, which is consistent with geological evidence. The Silurian and Devonian paleomagnetic results from the AHC terrane may therefore be used to discuss the middle Paleozoic tectonic displacement and paleogeographic reconstruction of the NCB. ¿ 1999 American Geophysical Union