A field study was conducted from 2005 to 2007 with the objectives to determine the growth and development characteristics of dwarf cotton line Lu-ai No.1.The results showed that there was no significant differences in morphology at seedling stage among different cotton varieties.However,the difference became more and more obvious with growth and development progressing.Daily increasing growth amount of main stem of Lu-ai No.1 was significantly lower than that of normal varieties at every growth stages except for seedling stage.The daily increasing peak stage was the same among different varieties,but the daily growth amount of Lu-ai No.1 was lower than that of normal varieties,and the increasing amount of main stem was very small after midbloom stage.At the end of growth stage,the plant height of Lu-ai No.1 was only about half of that of normal varieties,the number of fruit branches,internodes,fruit sites per fruit branch and the length of fruit branch were obviously lower as well.There were no significant differences in internodes length under the 12th nodes of main stem,but the upper internodes length of main stem was significantly lower in Lu-ai No.1 than in normal varieties.Compared with the normal varieties,the growth duration of Lu-ai No.1 was shorter,bolling sites and time was more concentrative.