Abstract: This article analyzes the division and restriction of horizontal powers of American constitutional system through the case of Marbury v. Madison. And It describes the conflicting, mutual effect , checking and supervising between the three kinds of powers objectively. Although the system of American horizontal division of powers is thought to be the typical constitutionalism model in many counties, many problems have arosen. We must treat this system which formed under the direction of the theory of separation of powers rationally.

Key words: Marburyv, Madison, separationofpowers, horizontaldivisionofpowers, restrictionofpowers