The purpose of this study was to observe the changes of skirt length of knitted flare skirts when the seamless test garments were made which had been having full shape while being knitted and to change and amend the challenges in advance when those were knitted. For this study, I made 6 kinds of knitted test garments of wool 100% yarn with seamless knitting machine, which differed from each other by skirt angles ($90^{circ},;180^{circ}$) and gauges (7G, 12G, 15G), and then I measured deflection changes of their length for 2 weeks. Findings and conclusions drawn from this study were as follows: First, the side seam line of full shape hecame somewhat longer than center. Second, 7G and $180^{circ}$ knitted flare skirt showed the biggest length deflection changes. Third, there was no difference at rear waist deflection changes between front pattern and rear. Fourth, it was difficult to control the tensions of right and left strings as to the knitting directions.