PURPOSE: To provide the new compound safely and easily inducible to 1,2,3- triazole by cyclizing with a dehydration agent and usable e.g. as a production intermediate for 1,2,3-triazole useful as a raw material for antibiotic substance.

CONSTITUTION: The glyoxal monoxime hydrazone of formula II can be produced by dissolving 2,2-dichloroacetaldehyde in water, adding an aqueous solution of hydroxylamine hydrochloride to the solution, reacting at room temperature for 2hr under stirring to obtain 2,2-dichloroacetaldoxime of formula I, adding the compound to a mixture of hydrazine monohydrate and methanol under cooling, reacting for 1hr under stirring while keeping the system at 10°C or below, removing the precipitated hydrazine salt formed as a by-product, concentrating the filtrate and purifying by silica gel column chromatography. The compound of formula II is cyclized by reacting with a dehydration agent to safely and easily obtain 1,2,3-triazole expressed by formula III.