Abstract: Based on analysis of the four characters of ecoeconomic system of arable land in China: the fluctuation in motion,comples in structure,frailty in constitution and delayed management,it is concluded that by carrying out the monitor of the dynamics of arable land ecoeconomic system,the management of arable land can be changed form static and passive states to dynamic and initiative states to realize the goals of adjustment of the arable land ecoeconomic system in advance and effectively protect the arable land.Then the basic meaning,sources,signs and degrees of the forewarning system as well as the train of thought and methods for forming the mechanisms of monitoring the dynamics of arable land ecoeconomy in China are extensively discussed in the paper.