Geothermal is one of the geophysical fields, and geothermal energy is the indigenous energy source on the earth. Li Siguang (J.S. Lee) launched geothermal science program in China in 1960s. After a few decades of growth and development, the discipline became comprehensively established by mid 1990s. During last 20 years, the scope of geothermal research in China has been further expanded and deepened. This paper reviews the key highlights of the innovative advances in several respects, including terrestrial heat flow measurements,thermal structure of the lithosphere,geothermal systems,geothermics in oil and gas-bearing basins, geothermics in mines, natural gas hydrates, and climate change. Also prospects are included for deep geothermal resources, marine geothermal resources, and environmental geothermics. The authors believe that, geothermal research made significant progress in China in the last 20 years,which has provided backstopping for geothermal industry in China, and its continued fast growth can be expected. International collaboration has been strengthened. It is also postulated that geothermal research will further broaden its scope of study, after going from the upper crust to the deep earth's interior and from the present regime to thermal history of basins, making more substantial contributions to the development of geodynamics, and to safe-guarding the energy supply and environmental wellbeing of the country.