The Alxa block is a Precambrian microcontinent bounded by orogenic belts and fault zones, and its property and tectonic affinity have always been controversial. Based on the recent research data obtained by the author in the eastern Alxa block and combined with the research progress of Alxa block in recent years, it is considered that the 2.64 Ga amphibolite and ~ 2.5 Ga TTG gneiss exposed in the eastern Alxa block, and clearly indicates that Neoarchean metamorphic basement also exists in the eastern Alxa block. The zircon Hf isotopic data of these Neoarchean metamorphic rocks show that the model ages mainly range from 3.38 Ga to 2.88 Ga, which are consistent with the Hf model ages (3.4 ~ 2.6 Ga) of the Paleoproterozoic zircons from the Diebusige Complex and Bayanwulashan Complex in the eastern Alxa block. The above data indicate that the eastern Alxa block has experienced crustal growth from the Late Paleoarchean to Early Neoarchean and magmatic-metamorphic event of the ~2.5 Ga. In addition, the magmatic event of 2.3~2.0 Ga and magmatic-metamorphic events of ~1.95 Ga and ~1.85 Ga were also recorded in the Early Precambrian basements of the eastern Alxa block, similar to that of the western Alxa block and the North China Craton. Based on the similarities in the zircon chronology data and Hf isotopic compositions of the Early Precambrian basements from the Alxa block and the Khondalite belt, we proposed that the Alxa block has a similar crustal evolutionary history with the Khondalite belt, and was probably involved in the Khondalite belt as its western extension in the Paleoproterozoic.