  I report BESIII preliminary results on:
  1 Measurement of sigma(e+e- ->DDbar at Ecm = 3.773 GeV
  2 Study of the DDbar production line shape near Ecm = 3.773 GeV
  3 The first observation of singly Cabibbo-suppressed decay, D -> omega pi
  4 Measurement of BF(Ds+ -> eta' X) and BF(Ds+ -> eta' rho+) .
