Abstract: This study is analysised on circle collar size of knitting cloth.The data of front and back arc length of circle collar of knitting cloth was measured on culture prototype of Japanese women dress （160/84A）under the certain neck width and analysised, the variation of front and back length of circle collar of knitting cloth were known,the math models were developed for front and back of circle collar of knitting cloth through regression analysis.The study provided an important reference to the pattern design of knitting cloth，and laid down a technology foundation for garment intelligent production．

Key words: round collar, knitted woolen sweater, statistical analysis, mathematical model, pattern design