To research the behavioral conduct of dyes, in a practical compound to achieve required leveling and confidence of requested shade, repeat ability, minimum amount of dye and consumable energy is essential. During the recent years there have been tremendous changes in different industries and textile industry is no exception to these changes. As the processing of dyeing become more complex, due to decrease in its cycle, control by computer to know more about the levels and methods seems to be necessary. Therefore, shorter dyeing cycles will increase production and decrease the level of chemical usage. In addition to achieve leveling by adding chemical auxiliary, increasing the temperature or maintain during long and additional hours has been kept a side and use of compatible dyes since rate of speed during the dyeing period there should be an equal percentage of exhaustion which is acceptable. Incompatible dyes during different times of dyeing have attractive speed stroke and as a result produce an un-level dyeing. More over repeat ability can not be achieved. The purpose of this research is a method to determine the compatibility of Disperse dyes in mixture, based on the application of principal component analysis on the spectrum data’s. To achieve this purpose, scalability of each dyes have been computed in different temperature and different time at highest temperature of dyeing cycle for three different shade according to standard depth of used dyes .In order to eliminate the errors which originate from the non-linearity of K/S function against dyestuff concentration, first the scalable region in the K/S spectral data for used dyes has been determined as the priority by principal component analysis (but the results did not limit to this region only). Thereafter, according to the quantity of absorbed dyes and rate of build-up for disperse dyes toward used concentrated, speed curve of dyes was achieved in pale, medium and dark shade. Afterwards speed curve of mixture samples were achieved in comparison on components dyes. Finally, by using principal component analysis on the K/S spectral data, the elements of data and eigenvalues have been determined and the calculated percentage variance, as an index of compatible-incompatible existing components in mixture has been calculated. The achieved results were compared with the method of compatibility definition by BE i (t) (fraction of bath exhaustion). The obtained results confirmed the applicability of suggested method. Some additional methods such as interpretation of normalized K/S spectrul curves of mixtures, computation of unit k/s values from the linear transformation of the eigenvectors of databases and the calculation of dyestuff concentration from the spectrul data are employed too. The accuracy and the efficiency of calculated scale has been compared with the achieved results in this method for the compatible business dyes which has been studied and examined. Also this method was been compared with the one of previous researches; the computation of adjusted exhaust value and determined that method can not be used where percentage of components in mixture are close to each other. According to achieve results principal component analysis can be used for computing an index to determine compatibility of Disperse dyestuff.