An object of the present invention is to provide a method of gene introduction, which can transform a Hordeum plant at a higher efficiency compared to that in known Agrobacterium methods, and a method of producing a transformed Hordeum plant. The method of the invention includes a step of subjecting an immature embryo tissue of a Hordeum plant to centrifugation treatment and/or pressurization treatment before the inoculation with Agrobacterium, during the coculture step, and/or after the coculture step, and is characterized in that the coculture medium satisfies at least one of a) containing an antiauxin b) containing a cytokinin and c) containing a phenoxy auxin in an amount of less than 2 μM and/or a benzoic auxin in an amount of less than 5 μM, or not containing any phenoxy auxin and/or benzoic auxin.
