The present invention relates to a method for preparing amicarbazone by using amino-triazolinone, which is an intermediate compound, and relates to a method for preparing amicarbazone, comprising the steps of: obtaining hydrazine carboxylic acid represented by 5 chemical formula (V) by reacting acylhydrazide represented by chemical formula (II) and a carbamating agent represented by chemical formula (III) or (IV) reacting the obtained hydrazine carboxylic acid represented by chemical formula (V) and hydrazine hydrate in the presence of a base catalyst and reacting the obtained compound represented by chemical formula (I) 10 and an alkyl isocyanate represented by chemical formula (IV) in the presence of a base catalyst. Amino-triazolinone and amicarbazone would be stably produced by the present invention without safety gear and safety facilities for the leakage of phosgene, which has been conventionally used as a reactant.
