The present invention relates to a composition for screening antihypertensive drugs, which contains a mammalian TCTP gene or a protein expressed therefrom, as well as a method for screening antihypertensive drugs using the composition. TCTP contained in the inventive composition acts as a cytoplasmic inhibitor of the Na/K APTase pump, thus causing hypertension and heart hypertrophy. Therefore, the inventive composition and the screening method using the same will be useful for the investigation and development of antihypertensive drugs. Furthermore, the inventive TCTP-overexpressing transgenic mice shows hypertension or heart hypertrophy as a phenotype. Thus, the inventive transgenic mice will be useful in screening test substances developed for the treatment and improvement of hypertension and heart hypertrophy, by administering the test substance to the transgenic mice and observing the extent of treatment and improvement.