Woven and nonwoven fabrics present filtration efficiency higher than other air filtration media. Fabrics are selected according to air flow conditions and particle characteristics. The majority of air filtration media are nonwoven fabrics because of their cost, but they need high filtration area for high efficiency. Modified construction of woven fabric introduces high performance in air filtration and decreases filter size, which tends to have better competition abilities. The designed fabrics have considerable thickness and suitable pore characteristics by applying roving instead of weft yarns. Four factors (roving count and their turns per inch, picks per inch and fabric designs) were varied in order to study the effect of these factors on their performance in filtration. Optimum operating conditions for a determined range of air permeability and pore size were obtained.