To determine the effects of slow-released fertilizer application on the growth and yield formation of rapeseed in Yangtze river delta，meanwhile to improve the yield and resource utilization，a field experiment was conducted in Suzhou，Jiangsu province from 2020 to 2021. The slow-released formulated fertilizer was adopted at four different levels of 750，900，1050 and 1200 kg/hm²(F750，F900，F1050 and F1200)as well as the treatment without fertilization(CK). The yield，yield components，dry matter accumulation，nitrogen uptake and fertilizer use efficiency were measured. The results showed that the yields of rapeseed with slow-released fertilizer were significantly increased by 1.81~2.67 times，and the yield and fertilizer contribution rate were the highest with the application of 900 kg/hm²(P<0.05)，while there were no obvious difference among other fertilization treatments. The yield of rapeseed was significantly correlated with the number of branches，siliques and plant height. The number of rapeseed siliques in F900 was significantly higher than those of F1050 and F1200(P<0.05). No significant difference was found on seeds number and thousand-grain weight. The plant height of rapeseed gradually increased with the increase of slow-release fertilizer dosage. The dosage of 750 kg/hm² obviously inhibited the dry matter accumulation and nitrogen uptake in the shoots of rapeseed at the seedling stage，and it was significantly increased by 38.8% at the amount of 1200 kg/hm²(P<0.05). The performance of 900 and 1050 kg/hm² were in between 750 and 1200 kg/hm². At flowering，the crop growth and nitrogen uptake at the level of 900 kg/hm² were significantly superior to other treatments，the crop growth rate were significantly decreased by 17.4% in F750 and 14.9% in F1200，respectively. The nitrogen uptake rate of rapeseed showed the same trend with the crop growth rate. At the seedling stage，the contribution rate of fertilizer was obviously improved with the increase of fertilizer application，while the agronomic efficiency was decreased significantly. The concentration of soil available nitrogen was increased firstly and then decreased with the increase of the slow-released fertilizer dosage at final-flowering stage. In conclusion，under the conditions of this study，the amount of 900 kg/hm² slow-released fertilizer which contained N 225 kg/hm²，P2O5 63 kg/hm² and K2O 72 kg/hm² was suitable for balancing the dry matter accumulation and nitrogen uptake between different growth stages for rapeseed，thus to improve the number of branches and siliques of rapeseed and enhance rapeseed yield，meanwhile to improve fertilizer use efficiency.