This article studies the land market system of our country from the angle of equality of the powders and functions of land use and the essential unification of land market, the main purpose of which is to try to build up a theoretical support, correct path and target for establishing a unified land market system. Thus, first, it analyses the typical dual characteristics of land market system structure, then the origin, contradictions and harm caused by separation of urban and rural land market; second, it studies the essential requirement of a modem unified market and the establishes a theoretical framework of changes of land market system, it also analyses and proves the paths and the goal choices for innovation of land market system of our country, establishes the theoretical model of unified urban and rural land market structure ; and finally, it raises policy suggestions for systematic innovation of unified land market on this theoretical model.