The hydroconversion of a mixture of rosin acids over a Pt-containing mesoporous aluminosilicate catalyst has been studied. It has been shown that in a temperature range of 300-350A degrees C at pressures of 30-50 atm and a feedstock/catalyst weight ratio of 20/1, rosin acids undergo complete decarboxylation to form naphthenic and naphthene-aromatic hydrocarbons. Under optimum process conditions, the yield of diesel fuel hydrocarbons is more than 85%. The resulting fraction can be used as a fuel component.