Abstract: In order to promote the popularization and application of a new maize variety Heyu 123,the breeding process, yield performance, characteristics and related cultivation techniques were introduced in detail in this paper.Heyu 123 is a new corn variety, it was bred by Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences, with self bred dent type line Hexuan 04 as female parent and self bred Medium flint type line Hexuan 21 as male parent. From 2018 to 2019, the average yield of participating in the regional trial of Heilongjiang Province consortium was 11 119.8 kg·ha^-1,increasing by 8.1% compared to the control variety Demeiya 3. In 2020,the average yield of the consortium production experiment in Heilongjiang Province was 11 910.9 kg · ha^-1, increasing by 7.1% compared to the control variety Demeiya 3. In 2021,it was be approved by the Heilongjang Crop Variety Approval Committee, appronal number was Heishenyu 2021L0020.It has the characteristics of high yield potential, high and stable yield, strong resistance to disease and stress. This variety is suitable for planting in the accumulated temperature≥10 ℃ and the active accumlated temperature is above 2 400 ℃.