Abstract: Thermal fluid in formation is a geologic concept and is the function of pressure and temperature in a basin. Concerning thermal fluid in formation,abnormal temperature field and abnormal pressure field are studied,then the influence of thermal fluid on organism evolution is considered. Basedon existed research achievement to thermal fluid, it is pointed out that thermal fluid can act as promotion and encumbrance when it act on organism in formation.

Key words: thermal fluid in formation, temperature filed, pressure field, hydrocarbon evolutio