Abstract: The paper aims to explore the effect of different planting densities on agronomic traits and yield of rice. The author took new Helong rice varieties ‘ ( uzhenxiang’, ‘Nongxiang32’ and ‘Yiyou673’) as materials, and set 3 different planting densities: 15×104 bunches/hm2, 18.75×104 bunches/hm2 and 22.5×104 bunches/hm2 to study their effects on growth stage, disease resistance, botanical characters and yield of rice. The results showed that: the planting density had little effect on the growth stage and the incidence of rice blast; high planting density increased the incidence of rice sheath blight and effective panical numbers, decreased the tiller numbers and the total spike grain;‘Yuzhenxiang’and‘Nongxiang32’had the highest yield at a planting density of 18.75×104 bunches/hm2, and‘Yiyou673’had the highest yield at a planting density of 22.5×104 bunches/hm2; among the 3 varieties planted at the 3 densities, the combined yield of ‘Yiyou673 (A3)’×density B3 (the bunch distance between was 20.2 cm) was the highest of 11.04 kg, and the yield increased by more than 6% compared with the other two varieties. Therefore,‘Yiyou673’ is recommended as the preferential variety in Helong rice production with the planting density of 22.5 × 104 bunches/hm2.