Abstract: Historic towns possess significant historical heritage and cultural value, carrying a rich array of historical spatial information. Research on spatial gene information chains facilitates the systematic understanding of spatial information context in historic towns, thereby providing scientific guidance for their conservation and sustainable development. From the perspective of spatial gene theory, this paper proposes a research framework for analyzing the spatial gene information chain of historic towns, structured as ‘Indicator System-Element Extraction-Structure Construction-Feature Interpretation'. Using Qingyan Ancient Town in Huaxi District, Guiyang City, Guizhou Province, as a case study, we establish an indicator system for identifying spatial gene elements. Through this system, spatial gene elements in Qingyan Ancient Town are systematically identified and extracted, enabling the construction of a four-dimensional hierarchical structure of the spatial gene information chain (‘Element-Cluster-Chain-Morphology') and an analysis of its defining characteristics.Adopting the spatial gene information chain as a research lens offers critical insights for the effective preservation and digital storage of spatial information, the accurate identification of material spatial features, and the rational classification and optimization of spatial configurations in historic towns.