The Bombyx mori silk fibroin/Tussah silk fibroin (SF/TSF) nanofibers with diameters between 300 and 3500 nm were prepared by electrospinning with the solvent HFIP The average diameters of SF/TSF blend fibers increased from 404 to 1977 nm, with the increase of SF content in blend solutions, and the relationship between the average diameters of SF/TSF and SF content was proved to be linear correlation. Results from FTIR, TG-DTA and X-ray diffraction showed that the electrospun fibers were mainly beta-sheet structure and, heterogeneous micro-structures. In particular, the presence of two different endothermic peaks at 300 and 360 degrees C in the TG-DTA curves may be ascribed to the thermal decomposition of SF and TSF. These results suggested that SF and TSF were still immiscible even dissolved in hexafluoroisopropanol (HFIP) after electrospinning and ethanol treatment. Moreover, the thermal decomposition temperature and enthalpy were improved with the blend of SF and TSF, else the SF/TSF nanofibers' moisture absorption was higher than the pure SF or TSF nanofibers. To study the cyto-compatibility and cell behavior on the SF/TSF nanofibers, MSCs, VECs, and Neurons were seeded onto the nanofibers. Results indicated that the SF/TSF nanofibers promote cell attachment and spreading, suggesting that these nanofibers could be a candidate scaffold for blood vessel and nerve injury recovery. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.