Microorganisms are one of the most dangerous damage factors that threaten archaeological cellulosic textiles such as cotton and linen. This research presents a detailed study of the effect of fungi that have been isolated from the display and storage environment of Sohag National Museum on the mechanical, physical and chemical properties of archaeological linen textiles. The study used the potato Dextrose Agar, PDA. Nutritional medium in conducting microbial surveys of the museum display and storage environment; the result of the survey was the presence of three fungal strains, Aspergillus flavus, Trichoderma sp. and Penicillium duclauxii, which dominated the display and storage atmosphere in the museum. The study evaluated the effect of these fungal strains on the linen textiles. Measurement of mechanical properties (tensile strength and elongation), change of color using the CIE Lab system and the use of Fourier transform infrared spectroscopy (FTIR) were used for the evaluation process. The results of this study found that the most dangerous fungal strain that affect both mechanical, physical properties and chemical composition was strain of Aspergillus flavus.