Abstract: With the popularization and application of mechanization, light, simplified and efficient cultivation technology of rapeseed, it is one of the goals of rapeseed breeding to select the varieties with characteristics of high-yield, density-planting tolerance and suitable for mechanized cultivation. YD 4899 is an innovative material of Brassica napus, which was bred by pedigree method, and its double main stem ratio reached 47.53%. To explore the characteristics including high yield, density-planting tolerance and suitable for mechanized cultivation of YD 4988, the phenotypic characters of YD 4988 were compared. The results showed that the average height and the average height of branches in double main stem variety were 8.26 cm and 31.80 cm higher than those of in single main stem one, while the average number of branches and the average number of scones per plant in the former were 6.09 and 103.08 more than those of in the latter, respectively. In addition, the average yield per plant and the average biological yield in double main stem variety were 18.41 g and 48.46 g higher than those of in single main stem variety, and the harvest index in double main stem variety increased by 11.47%. The average length of the inflorescence in former was 5.37 cm shorter than the latter, while the average number of siliques in main inflorescence was the same. However, the average number of seed per pod and 1 000-kernels weight of double main stem variety were 1.18 granule·kernel^-1 and 0.35 g less than those of single main stem one. The restorer line could provide new breeding materials for the breeding of innovative and breakthrough varieties.