Background:  Enterobacter cloacae is a bacterium that leads to soft rot in many diverse types of vegetables & crops across the world. At this time nanotechnology is utilized as a nanomaterials strategy for controlling plant pathogenic bacteria and maintaining postharvest quality.  Methods: The soft rotten tissues were collected from infected potato tuber and macerated in buffer saline solution. 50 uL of macerated sap was inoculated on selective King, B medium for isolated pathogenic bacteria. PCR was utilized to identify the isolated bacteria according to their morphology and the 16S rRNA gene. A randomized complete design was applied in the protective by Ch-MSNPs20nm@HTCC in postharvest. Results: Typical colonies on King, B medium were circular, moist, smooth, and entire margin, flat and fluorescent diffusible pigment in medium that identify Enterobacter sp. As well as phylogenetically it identified Ent. cloacae based on 16s RNA gene. Ch-MSNPs20nm @HTCC sprayed on infected potato tubers postharvest significantly reduced the disease severity, lowest HBS and AUDPC values and increased weight of healthy tuber tissues compared with Ampicillin as a positive control. In addition, it has the ability to prevent isolated Ent. cloacae from forming a biofilm. On the other hand, it has efficacy in increasing the longevity of potato tubers at postharvest.