Hexagonal M-type barium ferrite $BaFe_{12}O_{19}$ was prepared by a direct solid state reaction between $BaCO_3$ and ${Alpha}-Fe_2O_3$ powders at temperatures ranging from 800 to 1000 $^{circ}C$ in a nitrogen or air environment. The effects of NaCl on phase transformation of mixture of $BaCO_3$ and ${Alpha}-Fe_2O_3$ to $BaFe_{12}O_{19}$ were studied using X-ray diffraction and M$"{o}$ssbauer spectroscopy. Regardless of the environment for heat treatment or the added NaCl, two phases, BaFe and ${Alpha}-Fe_2O_3$, coexist for samples heat treated at 800 $^{circ}C$, but a single phase was observed from samples heat treated at 100$0^{circ}C$ in both air and nitrogen environments. It was found that the addition of NaCl reduced the amount of $a-Fe_2O_3$ phase.hase.