In this study, activated carbon (AC) enhanced hydrophobic/hydrophilic dual-layer nanofiber composite membranes were prepared for direct contact membrane distillation (DCMD) by incorporating different concentrations (0-3.0 wt%) of AC nanoparticles into the polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) hydrophobic active layer. The membranes were composed of two layers, a thin hydrophobic PVDF-HFP/AC electrospun active layer and a thick hydrophilic support layer. Results indicated that the incorporation of AC nano particles have greatly increased the membrane properties and performance. The membrane containing 1.5 wt% AC nanoparticles (M3) showed the best flux performance (45.6 L/m(2) h) compared to other membranes fabricated in this study and a commercial PTFE benchmark membrane (41.8 L/m(2) h) without compromising the salt rejection. A two-dimensional model was developed to investigate the flux profile of the PVDF-HFP/AC membranes. The present study suggests that the incorporation of AC nanoparticles into PVDF-HFP active layer can impart additional functionalities to the composite membranes that would enhance the membranes DCMD performance. The fabricated PVDF-HFP/AC composite membranes present great potential in the application of DCMD desalination.