It has been a hot-debated issue in geological field when the North China Craton was amalgamated with the Alxa block together. This paper reports new data on both the sedimentary structures, such as cross-bedding and ripples, and structural deformation of Devonian and Carboniferous strata exposed in southwest slope of the Niushou Mountains, Ningxia, Northwest China. In combination with available debris zircon aging spectrums of Ordovician sandstones, it is supposed that the amalgamation of the North China Oraton with the Alxa block took place in a geological time between Late Ordovician and Early Devonian.