Buildings in the United States and China consumed 41% and 28% of the total primary energy in 2011, respectively. Good energy data is the cornerstone to understanding building energy performance and supporting research, design, operation, and policy making for low energy buildings. This talk presents initial outcomes from a joint research project under the U.S.-China Clean Energy Research Center for Building Energy Efficiency (CERC-BEE). The goal is to decode the driving forces behind the discrepancy of building energy use between the two countries; identify gaps and deficiencies of current building energy monitoring, data collection, and analysis; and create knowledge and tools to collect and analyze good building energy data to provide valuable and actionable information for key stakeholders. A detailed, measured building energy data comparison was conducted for a few office buildings in both countries. Finally issues of data collection, quality, sharing, and analysis methods are discussed. It was found that buildings in both countries performed very differently, had deep potential for energy savings, but that different efficiency measures should apply. BIOS: Tianzhen Hong is a Research Scientist with the Simulation Research Group. He is leading the Simulation and Monitoring research area under the CERC-BEE. Le Yang is a PhD student with Tsinghua University, China. Wei Feng is a Sr. Scientific Engineering Associate with the China Energy Group. The LBNL team has been working with a team at Oak Ridge National Lab and a team at Tsinghua University on the building energy monitoring project since July 2011.