To obtain more detailed and accurate pore size distribution for cotton fabric, this paper focuses on comparing size distribution between the yarn and fabric. The result shows that there are great difference as well as relationship in size distribution between the yarn and fabric. The size in fabric has 2 orders of magnitude including that in yarn with just 1 order of magnitude. The pore size ratio data also illustrate that the pore in yarn account for 33.3% of that in fabric, suggesting that the pore in yarn has a certain impact on the wicking behavior of fabric. However, the graphic exhibit that the size distribution shape in yarn is different from that in fabric, which may be owing to the fabric weaving configuration, implying that wicking liquid movement is affected not just by capillary effect along the yarn but also by interlacing points and fluid-wall interaction in the complex channels of fabric.