| This study was conducted to investigate the novel patern of cotton-wheat continuous cropping, and to realize the characteristics of cotton seedlings in growth and development, nutrient uptake, and yield formation. Field experiment was carried out in 2009 at Cotton Research Institution of the Chinese Academy of Agriculture Sciences (CCIR) in Anyang, Henan. Short-season cotton CCIR50 (Gossypium hirsutum L.)was separately sowed and raised in the greenhouse every 14 days since March 19th to obtain seedlings with 6 different seedling ages, and all seedlings were semi-mechanized transplanted to the field on June 12 (after wheat). Moreover, the treatment of direct seeding cotton was set as the control. There are 7 treatments with 3 replications in this study. The main results are as follows∶Short-season seedling cotton transplanted after wheat switched squaring 7-18 days, flowering 7-21 days, boll opening 6-19 days earlier than seeding of sowing.Before transplanting, Short-season cotton seedlings with age of 65 days, 50 days and 23 days were better in seedling quality, which had higher root to shoot ratio ranged 0.55-0.56, greater dry weight above 0.59 grams, appropriate plant height and leaf surface area, higher stem diameter of 0.2cm or more, and proper true leaf number of 2～3.5. With seedling transplanting technology, survival rate of seedlings with age ranged 16-78 days reached 94.9% or more.Compared with the direct sowing treatment, 50-day-old-seedling treatment increased seed cotton yield (3238.6 kg?hm-2) and lint cotton yield (1251.3 kg?hm-2) by 14.8% and 17.5%, respectively, which was the highest among all treatments. 23-days-old-seedling treatment increased cotton yield and lint cotton yield by 6.9% and 3.5%, respectively. There were no significant differences observed among all treatments in lint percentage. But direct sowing treatment was the lowest in lint percentage in value. The boll weight of direct sowing treatment was 3.42g, which was significantly lower than others. 50-days-old-seedlig treatment with 75.48% early flower raio was the greatest in all treatments, while the direct sowing treatment was the lowest with 45.6% early flower rayio. Fiber quality of pre-frost lint was significantly higher than that of post-frost lint. The phenotypic value of fiber length, fiber uniformity index, fiber elongation, fiber breaking tensile strength and micronaire reading of pre-frost lint was higher than that of post-frost lint by 3mm, 2.8%, 0.2%, 5.6cN/tex and 1.1, respectively. No significant difference was observed between different transplanting periods.The theoretic plant height ranged 62.8～76.1cm for short-season cotton transplanted after wheat. Seedlings of 23 days and 11 days were taller, with the fastest height growth period 37.5 (July 17th)～36.8 days (July 21st) after transplanting. Fruit branch number ranged 10.4～12.2; plant leaf area reached to the maximum of 3300～3800 cm2 in the end of August, and the maximum leaf area index reached 2.37～3.53. The number of reproductive branches per plant was roughly 34.4～40.7, and seedlings with age of 65 and 50 days had more than others.Dry matter accumulation of individual plant was simulated. The simulation equation showed seedlings with age of 50 days and 38 days were the greatest in dry mass, which were 96.6 grams and 96.3 grams, and the fastest growth occurred 110 days (August 18th) and 119 days (August 19th) after sowing, respectively. The simulation equation of dry weight of reproductive organs showed the fastest growth occurred 61.49 (August 27th)-76.29 (September 9th) days after budding. Logistic regression was achieved for individual plant nutrient uptake. The result showed, in theory, seedlings of 50 days was the greatest in nutrient amount, which is 4204.2mg, and the next is seedlings of 78 days, which is 4125.8 mg. The minimum nutrient amount was found in direct seeding treatment, which is 3456.2 mg. The maximum nutrient uptake rate occurred around August 1st. The absorption ratio of N, P2O5 and K2O during growth period was 1∶0.31～0.40∶1.04～1.22. The total uptake per plant reached 1.42～1. 60 g for N, 0.44～0.65 g for P2O5, 1.55～2.02g for K2O. Differences existed among growth stages.For all treatments, MDA content and activity of SOD in functional leaves were higher in seedling bed than in field period. In seedlings raised more than 50 days, leaves have higher enzyme activity at the later period .
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