According to the experimental results, it has been reported by several researchers that the air-permeability values of the fabrics mostly decreased by the mordanting during the dyeing procedure. The exact quantitative information, however, has not been presented so far. In this study, the change of the fabric air-permeability was investigated quantitatively. At the same time, the change of the fabric air-permeability according to the dyeing procedure. In order to investigate the possibility of the detachment of the metal ions on the fiber or fabric surface, the change of the air-permeability was investigated after several rinsing of the mordanted fabrics. By comparing the color differences of the cochineal dyed fabrics which were subjected to rinsing procedure after mordanting, the effect of the rinsing of the mordanted fabrics on the dyeing of fabrics was investigated. At the range of mordant concentration, 2% Cu, 2% Sn, 2% Fe, 2% Cr, 5% Al, the metal ions are not excessively absorbed on the fiber surface. Also, any remarkable detachment of the metal ions does not accompany after the mordanting with the subsequent rinsing procedure.