Mixture is that DNA profiles of samples contain material from more than one contributor, especially common in rape cases. In this situation, first, the method based on enumerating a complete set of possible genotype that may have generated the mixed DNA profile have been studied for interpreting DNA mixtures. More recently, the methods utilizing peak area information to calculate likelihood ratios have been suggested. This study is concerned with the analysis and interpretation of mixed forensic stains using quantitative peak area information and the method of forensic inference for extension of material from more than or equal to three contributors. Finally, the numerical example will be outlined.