Old historical papers always are suffering from yellowing and darkness specifically after natural aging, so this study aim to evaluated some traditional bleaching materials that used in treatments of documents and books like hydrogen peroxide and sodium borohydride. Physical and chemical changes in paper sheets (cotton linter paper and book) before and after aging were studied such as color change, pH measurements, tensile strength, burst strength, FT-IR spectrum and scanning electron microscopy (SEM). The result pointed out that H2O2& NaBH4 lead to a significant improvement on mechanical properties of the historical paper. The effect of H2O2 and NaBH4 concentration, bleaching time and pH on paper sheet bleaching process were examined. Whiteness and yellowness results of the historical paper were evaluated for both bleaching methods. From this work it is clear that, it is not desirable to utilize bleaching agents for the treatment and conservation of ancient archaeological papers, but only in the essential cases they may be used in slight concentrations to treat yellowing, staining or stains