egative Poisson's ratio materials or auxetic materials are type of non-conventional materials, which in contrast to conventional materials, expand laterally when stretched axially or shrink laterally when compressed axially. So far, a large number of materials with this performance are discovered or made. These materials have unique properties which makes them suitable for special applications. Auxetic textiles such as auxetic yarn, fabric and 3D textiles have attracted great attention in recent years. Up to now, two general structures of auxetic yarns have been proposed which can be used either in yarn or in woven fabric forms. However, the amount of researches in field of auxitic woven fabrics is limited. These mainly concentrate on the achievement of auxetic effect in fabrics and influence of structural parameters on auxetic property has not been investigated. Also, various auxetic knitted structures and 3D textiles have been produced by non-auxetic yarns. This research aims to achieve the following: Production of auxetic yarn using existing yarn spinning machine, Production woven fabric samples with the auxetic yarn as weft thread and verification of auxetic property in these samples, Evaluation the effect of structural parameters of woven fabric namely weft and warp densities, warp count and weaving pattern on Poisson’s ratio of the fabric. Hence, 39 samples of woven fabrics with different structural parameters and the identical weft yarn were produced. In order to investigate the Poisson’s ratio of the samples woven with conventional yarns, 19 woven fabrics were produced. Finally, the samples were loaded in weft direction and their dimensional changes at different strains, were recorded using an imaging system. Results were processed using an image processing technique based on MATLAB software. The results of yarn tensile test showed that the produced yarn behaved auxeticly in the used strain range. Minimum Poisson’s ratio of -0.9 was obtained. The results of fabrics tensile test containing auxetic yarns showed that in general these fabrics are auxetic in the stated range of strain. It was found that weft and warp densities and warp count influence the minimum value of negative Poisson’s ratio. It was shown that weaving pattern alone could not be the determinant factor for auxetic behavior of these fabrics. However, the interaction between weaving pattern and other structural parameter affect the auxetic behavior of fabric. The results of tensile test of fabrics woven with conventional yarns showed that the variation of Poisson’s ratio of the samples versus elongation always occur in the positive rang.