The present invention provides a process for producing the pyridine compound ÄdÜ: <;CHEM>; Äwherein R<;3>; and R<;4>; are as defined belowÜ, which has an excellent herbicidal activity, by making a pyridine compound ÄaÜ: <;CHEM>; Äwherein R<;1>; represents a C1-C6 alkoxy group, R<;3>; represents a halogen atom, cyano group or nitro group, and R<;4>; represents a hydrogen atom or halogen atomÜ react with an alpha -diazoester compound ÄfÜ: N2CHCOR<;1>; Äwherein R<;1>; is defined aboveÜ in the presence of an acid.