To provide a method for producing a (4,5-dihydroisoxazol-3-yl)thiocarboxamidine salt compound simply, safely and in good yield, whereby drawbacks of prior art have been solved.A method for producing a (4,5-dihydroisoxazol-3-yl)thiocarboxamidine salt compound of the formula (2): ##STR00001## wherein each of R.sup.1 and R.sup.2 which are independent of each other, is a hydrogen atom, an alkyl group or a cycloalkyl group, each of R.sup.3 and R.sup.4 which are independent of each other, is a hydrogen atom or an alkyl group, provided that R.sup.1 and R.sup.2, or R.sup.2 and R.sup.3, may be bonded to each other to form a cycloalkyl group together with the carbon atoms to which they are bonded, and X.sup.2 is a halogen or an anionic residue derived from an acid, which comprises reacting a 3-halogeno-4,5-dihydroisoxazole compound of the formula (1): ##STR00002## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, and X.sup.1 is a halogen, with thiourea in the presence of an acid.