GIS (Geographic Information Systems) play an important role to acquire and communicate geospatial knowledge based on spatial data and the use of spatial analysis, modeling, and visualization. The assurance of the validity and quality of spatial data handling and analysis remains a great challenge, in part, because of sophisticated procedures are often required for collaborative geospatial problem-solving and decision making. These procedures, when specified as knowledge derivation workflows, require carefully configured parameters and spatiotemporal specifications guided by specific contexts and purposes. The information of spatial data lineage and related analysis workflow is defined as spatial provenance in this research. Such information is often not well recorded or managed during spatial data handling and related analysis. This paper presents a provenance-aware GIS architecture that incorporates spatial provenance to address this shortcoming and facilitate the assurance of validity and quality of spatial data handling and analysis. Spatial provenance in this architecture is generated and managed to allow queries on data lineage and workflow information to support geospatial problemsolving. Basic elements of spatial provenance are captured using a spatial provenance model. The illustration of the provenanceaware GIS architecture and its proof-of-concept implementation reveals the similarity and difference in the use of spatial provenance in GIS applications. Overall, the architecture and implementation described in the paper demonstrates the necessity and feasibility of introducing provenance into GIS.