In order to understand the spatial-temporal distribution characteristics of cotton boll-formation under summer-sowing short-season-cultivation conditions, 10 cotton lines of different genotypes were used as experimental materials, and the occurrence of bud bolls in each part of cotton plants was recorded by plant diagrams. The results showed that in terms of time distribution, the peak period of buds was 56-80 days after seeding, the peak period of flowering was 77-96 days after seeding, and the peak period of boll-formation was 85-101 days after sowing, and the accumulation of reproductive organs(buds, flowers and bolls) of different varieties/lines was significantly different. Regarding to the spatial distribution, P56-3, 07 single 12, 07 single 6 and 07 single 7 showed the most bolls in the middle, while the rest of the varieties showed the most bolls in the lower part. In addition, the distribution of boll-formation rates of P56-3, 07 single 6 and 07 single 7 also showed“hollow shape in the lower fruit branches”. The yield structure of each line was significantly different, and the number of bolls per plant in 2003-29 was 19.53%-119.55% higher than those of other cultivars, and the yield of seed cotton and lint cotton was 21.82%-106.32% and 22.46%-134.05% higher than those of other varieties, respectively. Among 10 genotypes, the strain 2003-29 showed optimal characters including uniform boll-formation, less shedding, the highest number of bolls and yield per plant and thus it was suitable for planting in the summer-sowing short-season-cultivation mode. Therefore, the summer-sowing short-season-cultivation of cotton was mainly concentrated in August, and the traditional ratio of “three peaches” was not applicable to measure the boll- formation structure of high-yield and high-quality cultivation.