Abstract: A new synthesis with high productivity and simple process for 1 -amino-2, 4-imidazolidinedines is introduced. The product is prepared by condensation of semicarbazones, whose active-H is protected by aldehydic, with ethlmonochloroacetate in presence of sodium alkoxide in dry ethanl. This research not only increases its production rate, but also decreases the harm of poisonous regent to man.