Abstract: The transformational operation rules of narrowing and widening in knitting a woolen sweater is proposed.Based on the characteristics of narrowing and widening,integrated with corresponding equations,fourteen operation rules are given.The operation rules are divided into two major groups: the transformation of total needle number and turning number being the same,and the total needle number and turning number being different.In the former transformation,the operation rules of segments to increase,decrease and change under different terms are presented,and in the latter,operation rules for the total needle number and turning number being changing are set forth.