Multiple Critical Zone Observatories (CZO) have been established in recent years in the USA and other international settings to conduct collaborative research on processes that occur at and near Earth’s surface, also known as the Critical Zone (CZ). Data documentation and data sharing are two persistent problems facing the CZOs that impede the ability for cross-site comparisons and integrated analysis. In this study, a relational database was developed for CZ rock and regolith geochemical data – CZChemDB. There are a total of 24 interrelated tables in the database, each representing different aspects of CZ features. The main data group includes tables of locations, sites, samples, subsamples, preparation/treatments, laboratory-analysis and data values. The meta-data group includes tables of methods, references, and data quality. Lookup tables (variables, units, etc.) contain lists of “controlled” vocabularies. The CZChemDB is currently implemented in the MS Access database management system. It is expected to be integrated into the EarthChem portal by summer of 2011 for broader online accessibility and usability. This integration also complements the EarthChem’s global geochemistry database with CZ regolith data. The structure of the CZChemDB is simple, straightforward, and flexible so that it has potential to accommodate other chemical data collected from CZOs, such as pore fluid data. Furthermore, the development of CZChemDB represents the first attempt toward the standardization of geochemical data documentation and data sharing among CZOs. This effort will establish a model to bridge the connections between data acquisition, data management, data sharing, and data searching/discovering that are all essential but weak in terms of linkages within most geoscience research projects.