, (BNN) seed crystals Well-developed acicular Ba2NaNb5O15, have been successfully prepared by the reaction between BaCO3, Nb2O5 and molten NaCl salt. The effects of the calcination temperature, time, and weight ratio of the oxide mixture to salt on the morphology of BNN particles were investigated. Uniform acicular seeds with high aspect ratio could be achieved at 1200 degrees C for 4 h with the salt-to-oxide mixture of 2:1.