The effects of the type and the concentration of the co-solvent on the spinnability during cellulose electrospinning and the properties of the fiber were studied using cellulose dissolved in ionic liquid and co-solvent (DMF or DMAc). The prepared solution was electrospun onto a wired collector and coagulated in ethanol. As the weight ratio of co-solvent against ionic liquid increased, the spinnability was improved with stable whipping and splaying motion. Regardless of the co-solvent type, the higher co-solvent concentration resulted in finer fiber diameter, better web uniformity, higher crystallinity and better thermal stability. Comparing to DMAc, DMF showed more significant influence on the fiber diameter and the crystallinity. (C) 2012 Elsevier Ltd. All rights reserved.