In recent years nanofiber produced from electrospinning process, ecause of their high potential to use in different field including Biomedical Engineering especially in tissue engineering , Prostheses and implants ,Drug Delivery ,Wound healing and Skin , Have attracted much attention. Wound dressing produced with the use of nanotechnology is one of these utilizations from nanotechnology in recent years which helps to healing wounds. Polyhydroxybutyrate is a polymer with high Biocompatibiliy, However, existence of downsides like hydrophobicity and low rate of degradation have limited its applications. Therefore to improve hydrophilic and biodegradability properties , chitosan with different concentration added to polymer solution.because of low mechanical strength of chitosan , use of Polyvinylidene fluoride because of its high mechanical strength and biocompatibility is suitable for the strength of the dressing. For this purpose , the protective bilayer dressing of PVDF and PHB/Chitosan containing Gentamicin was produced with the aim of improving the mechanical properties for the treatment of postsurgical ulcers.In this research ,At first PVDF solution with concentration of 10wt% was prepared and electrospun. Then Polyhydroxybutyrate solution with concentration of 9wt% was prepared and chitosan with different concentration (10,15,20wt%) was added to phb solution , After preparation of the solution , gentamicin with different concentration (1,2,3wt%) was added to phb/chitosan solution and electrospun on the PVDF layer.to characterize the prepared scaffolds ,Scanning Electron Microscopy (SEM) ,Fourior transform infra-red spectroscopy (FT-IR) , Tensile strength test , Biodegradation test , In vitro drug delivery and Antibacterial test against E. coli were performed. According to the obtained results from SEM, Almost all nanofiber samples were uniform, also by examining the mechanical properties were observed that the addition of PVDF layer on PHB / Chitosan nanofiber layer has been improved mechanical properties and increased strength of scaffolds. FTIR spectrum showed that no specific interaction between the materials has occurred. Gentamycin delivery of nanofiber scaffolds showed a sustained release for 1 week, and all of the samples containing gentamicin showed good antibacterial properties. Key words: wound dressing, polyhydroxybutyrate, chitosan, Polyvinylidene fluoride, gentamicin, Elrctrospinning , Drug delivery