The present work was aimed at studying the effects of process parameters on morphologies of Polyvinyl alcohol (PVA) nanofibers in a novel electrospinning technique, bubble electrospinning. The process was optimized by constructing L 9(34) orthogonal experimental array design. Three factors were investigated and nine tests were run under lower, medium and higher levels of these factors. The results showed that PVA solution concentration plays an important role in affecting the morphologies of PVA nanofibers in bubble electrospinning process. With the increase of the concentration of PVA solution, the morphologies of fibers were changed from beaded fibers to uniform cylinder fibers and the average nanofiber diameter also increased. The optimization process was 12w% for PVA solution, 30kV for applied voltage and 10cm for spinning distance.