The present study was undertaken to evaluate the addition of nano-chitosan to kareish cheese for improvement their characters, including odour, tastes, colors and mycological quality. Out of 40 samples of kareish cheese were obtainedr and mly from retail farmers and supermarkets from different district in Giza Governorate, all samples were contaminated with fungi; the mean count/g was (1×10³±2.4). The most common isolated mould species were Aspergillus spp. which isolated from (80%) meanwhile; all samples were contaminated with different yeast species. The residues of AFM₁ were detected in 42 %, and theaccurate quantitative detection was observed in immunoaffinity column method than thin layer chromatography. The results revealed that the addition or coating with nano-chitosan (0.25% and 0.5%) before or after manufacturing of kareish cheese could cause their prolonged safe preservation as the nano-chitosan have the antimicrobial potential against several bacteria and fungi. Also, the colour, odour and taste of coated or added CSNPs cheeses were more accepted and palatable good characters were observed for a longer time of storage. Hence, it is anticipated that chitosan nanoparticles have the potential of becoming a powerful and safe natural antifungal agent. Therefore, the present study may provide the possibility of the addition of CSNPs to coating kareish cheese manufacture for quality improvement and extending its shelf life.