Abstract: In order to promote the popularization and application of a new maize variety Longdan 90,this paper briefly introduced its parental source,breeding process,yield performance,characteristics,cultivation technology and key points of seed production.Longdan 90 was bred by the High-yield Genetics and Breeding Laboratory of Maize Research Institute of Heilongjiang Academy of Agricultural Sciences in 2012 with self bred line H261 as female parent and self bred line G439 as male parent.It has the characteristics of high quality,multi resistance,high and stable yield and suitable for mechanized harvest.The variety was approved by Heilongjiang Crop Variety Approval Committee in April 2018（Heishenyu 2018050）.