The profile section of the man-made fiber can make a kind of process that the fiber imitates the natural fiber. Except increase the feeling of the fiber, at the same time, can improve the moisture absorption of the man-made fiber, increase the comfort worn. It will influence the property of the fiber that degree of profile which is big or small on profile section fiber. Because the spinning melting is a non-Newton fluid, the spinning condition will influence the swelling effect of spinning melting. While the fiber is spun the swelling effect will decrease the degree of profile. This research is to find the important factor of spinning condition which will influence the degree of profile on cross section fiber with experimental design and ANOVA.