The present invention relates to a synthesis method of metal cyclopentadienide by direct reaction of dicyclopentadiene with a group 1 metal in the presence of an aprotic solvent. Unlike the conventional method depending on retro Diels-Alder reaction of dicyclopentadiene to generate indirectly cyclopentadiene, the method of the present invention favors generation of cyclopentadiene and metal cyclopentadienide as well by adding dicyclopentadiene directly when the reaction temperature reaches in the boiling point of a reaction solvent.