The trial was conducted in field to probe the effects of N top-dress stage on yield and quality of Linyou 145,one wheat genotype with higher glutent content,and Linyou 2018,one wheat genotype with medium glutent content.The results indicated that yields of 2 genotypes were the highest when N top-dressed on the elongation stage,but protein content,wet glutent content,dry glutent content and sedimentation number etc increased as the N top-dressing late.The changes of flour quality index were different of 2 genotypes owing to the stage of N top-dressing.The quality of Linyou 145,which higher glutent content,was better by the N top-dressing in late spring,such as booting stage or heading stage,but the quality of Linyou 2018,which medium glutent content,was better when the N was top-dressed in the winter.