The invention relates to a therapeutic drug or a preventive drug for hypertension or high-normal blood pressure, comprising (a) and (b) as active ingredients:(a) a 2-phenylthiazole compound represented by formula (I) or a pharmaceutically acceptable salt thereof; (b) at least one compound or a pharmaceutically acceptable salt thereof selected from the group consisting of calcium antagonists, renin-angiotensin system inhibitors, diuretics, sympatholytic agents, vasodilators, and medicinally acceptable salts of these.The present invention also relates to a therapeutic method or a preventive method for hypertension or high-normal blood pressure, comprising administering the above (a) and (b) in amounts effective for treating or preventing hypertension or high-normal blood pressure.