Abstract: In this paper, the mulberry fibers were successfully obtained from the mulberry barks by a new pretreatment named alkali-assisted microwave plus biological enzymatic technique (AMBET). The chemical composition, morphology, microstructure and physico-mechanical properties of the mulberry bast fibers were investigated by means of SEM, FTIR, DSC, TGA, XRD and instron tensile tester. In particular, the antibacterial property of the mulberry fibers was evaluated by means of antibacterial testing. The results showed that the impurities of the bast fibers could be remarkably removed by AMBET treatment. AMBET treated mulberry fiber with diameter of (10.8±0.1)µm was even, smooth and fine. Typical celluloseⅠin the mulberry fibers was confirmed by FTIR and XRD analysis. The crystallinity of the AMBET treated fibers was higher than that of the raw mulberry and chemical treated mulberry fibers. Thermal analysis indicated that the mulberry fibers had a good thermal stability. Moreover, the AMBET treated mulberry fibers showed excellent antimicrobial activities with (80.4±2.1)% reduction against S.aureus. The physical properties of the mulberry fibers indicated the AMBET treated mulberry fibers had excellent spinnability.