The present invention relates to a low-temperature sinterable copper particle material prepared using an electride and an organic copper compound and a preparation method therefor and, more particularly, to a copper nanoparticle which can be useful as a conductive copper ink material thanks to its small size and high dispersibility, and a method for preparing the copper nanoparticle by reducing an organic copper compound with an electride as a reducing agent. The present invention provides copper nanoparticles which can be suitably used as a conductive copper nanoink material because the copper nanoparticles show the restrained oxidation of the copper, have an average particle diameter of around 5 nm to cause the depression of melting point, are of high dispersibility, and allow the removal of the electride in a simple ultrasonication process. The prepared copper nanoparticles can be useful as an oxidation preventing protector or conductive copper ink material which is small in particle size and high in dispersibility.