The plan of the Essential Function Region System of China advanced some grand theoretical issues in geography. First, the article considered the function region is the result of view of externality, and is different from the disparity regions in the past. The function region is stressed the act of the region to the others but not the difference between the regions. The auhur pointed out the character of the spatial act defined by externality, which distinguished the interactive act, and the faintness of the concept of action. It is pointed out, the geographical movement is the key to approve the externality and the space action. But it is difficulties to be approved because the difficult of the research means, which is the one of the grand theoretical issues faced with the Essential Function Region System. The another theoretical issue is how to plot out the boundary of the regions by difference space rule. It is evident that a natural territorial complex followed a region by differed rule and the process of economic development followed a rule of central place theory. It could be not confusion. Furthermore, the article considered the carrying capacity of resources and environment is a concept of passive viewpoint in which the advancement of the human civilization is ignored and the relations between the eco-environment on earth’s surface and the mineral resources under earth’s surface is not involved. The third theoretical issue is, related to the concept of carrying capacity, that is rational population be regarded as the object of the division plan. The article pointed out the population ration is accord with the geographical situation of carrying capacity basically in the history and in current theoretically, but in the fact, population transference could meet with many obstacles such as the international politics, the absent of opportunity of employment in developed area, the city management system and the regions of minority.