A method for producing nano-carbon materials, having a step wherein a starting material comprising one or more kinds of compounds selected from the group consisting saturated hydrocarbons, unsaturated hydrocarbons, saturated cyclic hydrocarbons, and alcohols whose atomic ratio of the component carbon to the component oxygen is more than 2.0 and a catalyst are together treated at a temperature in a range of from 100 to 800.degree. C. while being compressed at a pressure in a range of from 0.2 to 60 MPa.