Abstract: The International Symposium on Chinese Petroleum Exploration in 21st Century held in Hangzhou, Zhejiang Province on May 14-17, 2002 has drawn extensive attention from the petroleum communities both at home and abroad. The Symposium focused on China's oil and gas exploration prospects and targets in the new millennium as well as the other issues such as the relationship between the distribution of global oil and gas resources and world's populations and environments. The total amounts of oil and gas resources have increased steadily by a big margin in recent years in China. Future exploration will be directed to new petroleum provinces, new basins and new stratigraphic sequences and series. The scientific techniques for oil and gas assessment will be put forward, referenced to the foreign experiences, to apply to various regions including frontiers, immature and mature regions. The key of the resources assessments is to establish a new dynamic geo-economic evaluation system through data processing, specific studies and comprehensive evaluation of the reserves, risks and commercial values at a lower cost for promotion of the development of oil and gas industry in the world. To pick out the favourable prospects depends heavily on the establishment of geological concept and modeling, and the prediction of the modeling. The procedure involves tectonic basin analysis and simulation, hydrocarbon system studies, fair play evaluation, favourable horizon identification and prospect screening.