Abstract: With the gradual growth in global energy demand, energy supply has become a global strategic issue. It becomes more and more prominent that heavy oil is acting as an alternative energy with the gradual reduction of conventional oil and gas reserves. To take advantage of the research status of heavy oil's exploration and development, and thus to grasp the trend of their development, in this paper, survey and study are conducted based on a large number of research results of heavy oil including domestic and foreign research results. The definition, distribution, reservoir characteristics, formation and evolution, development techniques and upgrading techniques of heavy oil are summarized and a brief prospect of possible breakthroughs made in the is made. The research results may be good reference to the exploration and development of heavy oil.

Key words: heavy oil, reservoir characteristics, formation and evolution, development technique, upgrading technique, research status, prospect