Background/Question/Methods China is a rapidly developing country and has recently become the worlds largest emitter of carbon dioxide (CO2). International organizations and nations are increasingly concerned with global warming and with China’s contribution to global green house gas emissions. Chinese managed terrestrial ecosystems (especially grassland, secondary forests, and plantations) have great potentials for sequestrating C that could be used to offset the CO2 emission from fuel burning and land-use change, but estimates of current carbon sequestration are lacking. China has started several research projects to measure carbon inventories such as “ChinaFlux”, “Carbon inventory”, etc., but there is still no comprehensive and multi-disciplinary project on carbon dynamics in managed terrestrial ecosystems. Therefore, in October, 2003, United States and Chinese researchers met in Beijing to establish the “United States China Carbon Consortium (USCCC)” with the objective of providing a scientific basis for estimating carbon sink strength in these terrestrial ecosystems, and to serve as a baseline for international negotiations on carbon emission control treaties. Results/Conclusions Over the past four years, duplicate instrumentation and methodologies for measuring ecosystem carbon and water flux have been established in both countries. The project has already resulted in almost two dozen publications and spawned other collaborative studies. Research results and lessons learned from the collaboration will be presented.