Abstract: To clarify the effects of culture modes and population density on dry matter accumulation and yield in adzuki bean, two culture modes of flat culture and 65 cm ridge culture, five population density treatments of 9×104, 13×104, 17×104, 21×104 and 25×104 plants/hm2, were used in this study. Dry weight of different organs after flowering and yield components of post-harvest in adzuki bean were determined. The results showed that pod and grain amount of adzuki bean significantly decreased with the increase of population density, and the decrease of yield per plant resulted in no significant yield change with the increase of population density in flat culture. However, dry weight peak of nutrient organs in adzuki bean appeared later in ridge culture, and nutritive organs keep higher dry matter accumulation in seed-filling period, pod and grain amount increased by 3.8%-53.8% and 13.6%-101.5% respectively. Therefore, yield per plant and per unit area of ridge culture increased by 17.3%-127.2% and 36.8%-80.0%, compared with those of flat culture of the same density. In conclusion, the treatment of 17×104 plants/hm2 is fit for yield formation in ridge culture, however, planting density should be less than 21×104 plants/hm2 in flat culture.