Abstract: Panicle blast is one of the main types of late rice diseases in Hunan Province. The interaction of nitrogen application amount and seedling-throwing density was used in this research to study the influence on late rice panicle blast, and provide theoretical support for rice panicle blast control from the perspective of cultivation. This study set up four nitrogen levels (N1, N2, N3, N4) and three seedling-throwing densities (D1, D2, D3). The results showed that every disease development parameter presented a concave trend with density increase under the same nitrogen level, and an increasing trend was found with nitrogen increase under the same density. The disease development under N3D1 treatment reached the highest level, and the rate of disease panicles, disease plants, and disease index was 10.76%, 69.56%, 12.65%, respectively. The correlation coefficients R² of SPAD value with the rate of disease panicles, disease plants, disease index were 0.7294, 0.8325 and 0.746, respectively, all reached significant level. The correlation coefficients R² between leaf area per plant and the rate of disease panicles, disease plants, disease index were 0.8259, 0.8481 and 0.8407, respectively, and all reached significant level extremely. Nitrogen application of 180 kg/hm² and planting density of 262500 holes/hm² could promote the growth of late rice, and also reduce panicle blast.