This study was carried out in order to obtain the quantitative analysis of the seam puckering to the wale direction of plain-weft knit fabrics using moire topography, which enables us to find the way to evaluate seam puckering more systematically nowadays visual check of the defects improving the quality of sewing process. The total puckering value of plain-weft knit fabrics increases with values of the cover factor and yarn number. The seam pucker factor, fringe factor and surface unevenness factor increase with values of the cover factor and yarn number, respectively. The variation between cover factors is significant at the 1% level for all the specimens.