The recorded history for silage research has lasted for over 180 years. Since the initial studies on ensiling of fresh forages via salting and acidification, significant advances in silage science and technology have been achieved recently. All the achievements not only improved silage production efficiency but also provided animals with high-quality and safe feed resources for the whole year around, which greatly promoted animal husbandry and the livelihood of human beings. This chapter overviews the development of silage technology including ensiling facility, equipment, additives, forage processing and silo management; meanwhile, silage science related to characterization of ensiling biochemistry and microbial process is also discussed.