Abstract: The optimum planting density and fertilizer application level for the new variety of soybean with high protein, Quandou 17, were determined, which could provide theoretical basis for the efficient planting, promotion and application of this variety in the future. A two-factor complete randomized block design was used in the experiment. Five planting densities (D1-D5) were set up, which were 12, 18, 24, 30 and 360 thousand plants·hm^-2, respectively, and five fertilizer application level (F1-F5) were set up, which were 150, 300, 450, 600 and 750 kg·hm^-2, respectively. Then, the effects of different planting densities and fertilizer application levels on the agronomic characters, yield and quality of Quandou 17 were studied. The results showed that the plant height and bottom pod height increased with the increase of planting density, while the stem diameter, node number of main stem, effective branch number, effective pod number of single plant, grain number of single plant and kernel weight per plant decreased with the increase of planting density. Under the conditions of different planting density in D1-D5, the plant height, bottom pod height and node number of main stem increased with the increase of fertilizer application level. The stem diameter and effective branch number increased with the increase of fertilizer application level under the conditions of low planting density in the treatments of D1 and D2, while they increased first and then decreased with the increase of fertilizer application level under the conditions of high planting density in the treatments of D3, D4 and D5. The effective pod number of single plant, grain number of single plant and kernel weight per plant increased with the increase of fertilizer application level under the conditions of low planting density in the treatments of D1, D2 and D3, while they increased first and then decreased with the increase of fertilizer application level under the conditions of high planting density in the treatments of D4 and D5. The maximum value of plant height and bottom pod height appeared under the treatment of D5F5, and the minimum value appeared under the treatment of D1F1. The maximum value of stem diameter, node number of main stem, effective branch number, effective pod number of single plant, grain number of single plant and kernel weight per plant appeared under the treatment of D1F5, and the minimum value of those appeared under the treatment of D5F1. The yield increased first and then decreased with the increase of planting density and fertilizer application level. There was a certain negative correlation among the planting density, fertilizer application level and protein content, and the correlation coefficient was -0.146 and -0.002, respectively. Meanwhile, there was a certain positive correlation among the planting density, fertilizer application level and fat content, and the correlation coefficient was 0.263 and 0.020, respectively. The correlation between planting density and fat content reached the significant level. In summary, the optimum combination density and fertilization for Quandou 17 was D4F4, that was, the optimal planting density was 300,000 plants·hm^-2, the optimal fertilizer application level at this density was 600 kg·hm^-2, and the yield reached the maximum value of 2 217.40 kg·hm^-2.