To provide a method for economically producing a primary amine useful as a raw material for a polyamide, diisocyanate, etc., in a mild condition in good yield by reducing a specific primary dioxime in the presence of a hydrogenation catalyst.

A primary dioxime of the formula HON=CH-R-CH=NOH (R is a hydraccarbon) (e.g. 1,6-heanedialdioxime) is reduced in the presencce of a hydrogenation catalyst such as a Raney nickel, a Raney cobalt and Pd/C to provide the objective primary diamine of the formula H2N-CH2-R-CH2-NH2, such as 1,9-nonanediamine and 2-methyl-1,8-octanediamine in the method for producing the primary amine.