Abstract: Breeding of new silage corn varieties is one of the main directions of maize breeding in China. Since the start of national examination and approval procedure of silage maize varieties in 2002, a total of 28 new silage maize varieties had approved the national validation by 2017. In the development trend of chinese silage corn breeding research in planting density, biological yield and quality, the biological output is gradually improved and the quality is enhanced with the increase of planting density. However, there is still a high level of neutral detergent fiber content. The target of silage corn breeding is that planting density needs to be controlled within 75000-105000 plants/hm2 in order to ensure more green leaf area which can improve quality and biological yield. Meanwhile, grain yield can exceed or meet the contrast standard of normal corn to ensure adequate starch content(more than 25%). The variety has high resistance or immunity to leaf disease, ear disease and stem rot, and is also resistant to lodging. Furthermore, in case that the neutral detergent fiber and the acid detergent fiber meet the first-class national quality standard, the lower the content, the better the variety. In addition, when the protein content is more than 7%, the higher the content, the better the variety.