FIELD: organic chemistry, chemical technology, herbicides. SUBSTANCE: invention relates to method of synthesis of N-phosphonomethylglycine and its salts that are highly effective commercial herbicide useful for control of enormous variety of weeds. Invention describes method of synthesis of N- phosphonomethylglycine and its salts involving mixing aminomethylphosphonate, alkaline metal cyanide or hydrogen cyanide and formaldehyde to yield product followed by hydrolysis of product and isolation of hydrolyzed product with formation of N-phosphonomethylglycine or its salts. Reagents are mixed simultaneously and in the process of formation of the mentioned product regulation of pH value is not required. EFFECT: improved method of synthesis, simplified technological process. 22 cl, 1 tbl
