Towers, as monumental structures with profound cultural and religious significance, have been constructed throughout Chinese history. These buildings are now undergoing natural deterioration and anthropogenic damage, making detailed material studies essential for their conservation. Technical analysis of ancient bricks not only reveals historical manufacturing techniques but also helps in the evaluation of seismic performance, thereby providing vital information for the protection and restoration of ancient towers. This study investigated bricks from 13 ancient towers located in Shaanxi and Sichuan Provinces, China, particularly within the Guanzhong Basin, spanning approximately a millennium from the Sui to the Ming Dynasties. Utilizing techniques like SEM, XRF and XRD, we analyzed the microstructure and composition of the bricks to provide reference data for historical research and future restoration. The results indicate that regional variations had a significantly greater influence on the bricks than temporal changes during this period. Bricks from Shaanxi’s ancient towers exhibit higher Ca content and a more porous, loose microstructure compared to those from Sichuan’s towers. These characteristics merit careful consideration when assessing the weathering resistance of these historic towers and planning future conservation and restoration efforts.