A bicyclo[2.2.1]heptane derivative represented by following general formula (1): ##STR00001## wherein R.sup.1 and R.sup.2 each represent hydrogen atom or methyl group, and R.sup.3 represents methyl group or ethyl group. The derivative is suitable as a high viscosity hydrocarbon base material used for tackfiers for adhesives and process oils for rubber and resins.