Based on the review of the population big data of China, this paper analyzes current situation and problems of different population data sources. Despite the fact that population big data in China has very good historical accumulation, key population information has not been shared between different big data systems, and there are difficulties and challenges for deep data mining. During the big data construction and development, the problems that need to be dealt with are data structure standardization, data updating, sharing, privacy safety, real time data cleaning and data archiving. Since data structure is closely related to data analysis models, many demographic and statistical indicators will be reconstructed in future under the explorations of big data. This paper concludes with a discussion of the problems of constructing dynamic monitoring and early warning modules, indepth data mining framework as well as some major research areas.

The 6th National Population Census of China will be taken place in November 2010. It is believed that there will be more and severe challenges and difficulties in the 2010 census. How to meet the challenges and solve the difficulties is vital to census data quality. In this "Population and Development Forum", three census and data analysis experts are invited to discuss these issues. Professor Gu Baochang, from Center for Population and Development Studies of People’s University of China, assessed the historical importance of the 2010 census in the context of sustained low fertility, rapid ageing, rapid urbanization and massive migration in China. What he conveys is that our thinking has fallen behind the rapid and unprecedented demographic changes that are taking place in China. Dr. Wang Guangzhou, from the Population Institute of Chinese Academy of Social Sciences, discussed more technically on the census. He argues that the only solution to the difficulties is innovation, innovation in design of migrant survey, innovation in benefit-oriented mechanisms of census organization and conduct, and innovation in techniques in census chain of command. Dr Cui Hongyan, from the Population Section of National Bureau of Statistics of China, has been directly involved in the 2010 census design. She introduces the major innovative steps taken in the 2010 census in order to improve data accuracy, .the most important of these is the change of enumeration approach from permanent (de jure) residents to actual (de facto) population.