Here, chitosan/sericin/poly(vinyl alcohol) as a biodegradable nanofibrous membrane was prepared through electrospinning with and without silver nitrate. The influences of spinning conditions including volume ratio of chitosan and sericin, voltage and spinning distance at constant feed rate on the fiber morphology and size distribution were examined by SEM and Image J software. The FT-IR spectrum and EDAX were used to indicate the chemical structure of nanofibrous membrane. In addition, the effect of AgNO3 on the nanofibers diameter and its antibacterial activity was investigated. The optimum conditions obtained with chitosan:sericin (50:50, v/v), 22 kV voltage, 10 cm spinning distance at 0.25 mL/h feed rate to prepare nanofibers with small diameter and narrow size distribution without beads. The mean diameter of nanofibers was about 180 nm while introducing AgNO3 led to smaller nanofibers diameter about 95 nm. Moreover, the presence of AgNO3 produced an excellent antibacterial activity against Escherchia coli.