Through analyzing concept of agriculture and countryside, and overall objective of new socialist countryside construction “developed production, well-off living, civilized village culture, clean village environment, and democratic management”, this paper divides the informationization construction for new socialist countryside into agricultural informationization and rural informationization, and presents the new socialist countryside informationization construction system. Then the paper elaborates connotation of agricultural informationization and rural informationization, differentiates and analyzes the relation between the two concepts. Agricultural informationization and rural informationization influence each other, promote each other, and are integrated into new socialist countryside informationization construction.