A process for preparing acetamiprid, comprising: - taking cyanomethyl acetamidate in an organic solvent, - adding stoichiometric amount of cyanomethyl acetamidate to a mixture of a corresponding stoichiometric amount of 6-chloro-3-pyridalmethyl-N-memylamine and an organic solvent and refluxed at 30-35°C so as to obtain the product.