The preparations and properties of some 3,5-disubstituted-1,2,4-triazine-6-carboxylic acids and their derivatives were reported.Ethyl 3-thiono-5-oxo- or 3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylate reacted with aqueous ammonia or with hydrazine hydrate to give stable ammonium salts of the corresponding amides or the hydrazine salts of the corresponding hydrazides.But 3-thiono-5-oxo- or 3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazines and their 6-methyl derivatives could not form salts with ammonia.