  We present Doppler images of both components of the eclipsing binary system
ER Vul, based on the spectra obtained in 2004 November, 2006 September and 2008
November. The least-squares deconvolution technique is used for enhancing the
signal-to-noise ratios of the observed profiles. The new surface images reveal
that both stars of ER Vul show strong starspot activities and the starspots
appear at various latitudes. The surface maps of 2006 and 2008 both show the
presence of large high-latitude starspots on each component of ER Vul. We find
no obvious phase shift of the active regions during our observations. The
longitude distributions of starspots are non-uniform on both stars. At
low-to-mid latitudes, the active regions are almost exclusively found in the
hemisphere facing the other star. However, we find no pronounced concentration
of spots at the sub-stellar points.
