Over the reform period, industry has been the source of 40% of GDP, and has contributed 90% of China's exports. Annual firm-level surveys that begin in 1992, complemented with industrywide census in 1995, 2004 and 2008, are rich sources of data on firm behavior. It is well-known
that working with Chinese data requires overcoming difficult measurement issues. Macroeconomic series, for example, are often suspected of suffering from reporting bias and political interference. Working with the firm-level data has its own challenges. In this paper, we
provide an introduction to these data sets. We discuss and illustrate several of the issues that make comparability over time difficult and suggest solutions. The importance of a particular measurement issue often depends on the exact application. We illustrate this point by tracing
the evolution of the relative productivity level of entrants and incumbents over time, distinguishing between changes in actual performance and changes driven by measurement problems. We conclude by identifying a few promising areas of future research and margins on
which collaboration among users to improve these data might be beneficial.