Polyvinyl alcohol (PVA) was used to study the effect of LiCl on the variation of jet diameter with axial coordinate after the onset of whipping instability during electrospinning. Jet diameters at different points were measured by optical microscope. The results indicated that the addition of LiCl significantly accelerated jet thinning and solidification. It was found that average diameter of smooth jets decreased with increasing LiCl concentration. When LiCl concentration was equal or larger than 0.8 wt.%, surface charge became saturated and full charge on jet surface was obtained. The power exponent b in the allometric law was found to decrease with increasing LiCl concentration. (C) 2007 Elsevier B.V. All rights reserved.