In this study , a dyeing process of vat dyes was carried out for cotton fabrics (100%) at an optimal conditions for material's concentrations (sodium hydrosolphite , oxidization agent ,alkaline agent) to obtained a reference sample using for comparison with another samples which dyeing at difference concentrations of materials and different oxidization agent and conditions of works ( work at close condition or open) , and it was observed the decrease of fastness's values for the tester samples against dry and wet rubbing opposite of reference sample and that due to the difference of concentration of reducing agent and the weakness of bonds between the dye and textile because of the difference of oxidization conditions.