exocuticle and the fatty acids on the fibre surface, wool surface fiber has hydrophobic nature. This property accompanied by compact scale layer on the surface of wool fibre led to some problems on its processing. In order to obtain acceptable dimensional stability, good color yields, levelness and brightness in dyeing and printing of wool fabric, it is essential to modify the fibre surface using a suitable treatment. Because of increasing environmental legislation relating to adsorbable organohalogens (AOX), many chemical methods such as chlorination were limited and recent work has been focused on development of dry treatments with low or zero effluent. In this work, the effects of UV/O3 irradiation on the surface characteristics and dyeing properties of wool fabric have been investigated. Also, the influence of UV/O3 irradiation on kinetic (rate of dyeing), thermodynamic properties (standard affinity, heat of dyeing and entropy of dyeing) and the possibility of low temperature dyeing of the wool fabric was examined. In addition to UV/O3, the effects of ozone, UV and UV/O2 treatments on the wettability, shrink resistance, solubility in alkali, yellowness index, and tensile strength of wool fabric were evaluated. The results indicated that the wool fabric treated by UV/O3 for twenty minutes showed the best surface modification with instant wetting time along with minimum physical and chemical damages on the bulk fibres properties. This improvement in wettability could be due to the removing of the lipid layer on the fibres surface. Furthermore, because of the effects of surface modification, the remarkable enhancement in dimensional stability was obtained. As a result of short exposure time and the nature of irradiation process, the finishing process did not show any adverse effect on the substrate tensile characteristics. While the UV irradiation increased the fabric yellowness index, combining ozone in the process reduced the sample photoyellowing as a subsequent of the bleaching effect of the ozone. Moreover, the comparison of dyeing properties of the untreated wool sample with the UV/O3 irradiated one revealed an increase in the dyeing rate of both leveling and milling acid dyes due to the fibre surface modification by the degradation of the surface diffusion barrier. The photo-decomposition of surface lipid layer resulted in quicker wetting and swelling of wool, thus facilitating the diffusion of dyes by the intercellular route. Meanwhile, the photo oxidation of cross-linked disulphide bonds resulted in opening the transcellular route for dye diffusion. Similar results are obtained in low temperature dyeing of the milling acid dye. The thermodynamics examination of the samples illustrated a decrease in heat and entropy of dyeing for UV/O3 irradiated wool dyed with leveling acid dye, while the standard affinity did not change. This means that more dye can be retained in the irradiated fibre, that is, the interaction between dye and the irradiated fibre is increased.