This investigation was carried out to introduce natural dye extracted from the bark of Cassia Singueana plant used for dyeing of chrome tanned sheep skin crust leather. The colorant was extracted by aqueous extraction method and evaluated its absorption using UV-Visible spectroscopy (Lambda 25). The optimum extracted dye solution was obtained at temperature 95oc, concentration 60g/l and time of 60 min with absorption of 3.9 at λmax of 400 nm .The Possibility of using Aloe Vera juice and mango bark as natural mordants for leather coloration was also investigated. Dyeing was carried out with and without mordant at different temperature, time, pH and concentration of natural mordants. All three mordanting techniques; pre mordanting, post mordanting and simultaneous mordanting methods were evaluated. The color absorption (K/S) value and CIEL*a*b* values of the dyed leather samples were evaluated by using spectrophotometer (COLOR EYE-3100). The performance result with respect to light fastness, rubbing fastness and perspiration fastness values was evaluated as pre EN ISO 105-B02, ISO 11640 and ISO 11641 respectively. In most of the dyed leather samples the fastness result was in the range of good-excellent. Samples mordanted with the Aloe Vera shows better fastnes proporty as compared with control samples (unmordanted and mordanted with copper sulphate) and treated with mango bark. Similarly, color fastness of leather samples which were pre mordanted with Aloe Vera was better than that of post mordanted leather samples. The result of this study lead to the conclusion that the dye extracted from the bark of Cassia Singueana plant can be used as colorant for tanned leather with the selected natural mordants. Key words: Extraction, natural dye, natural mordant, barks, Cassia Singueana, leather.