An experiment was carried out to investigate the effect of $Na_{2}O$ additive on the magnetic and physical properties of $SrZn_{2}-W$ type hexagonal ferrite. The specimens were prepared by the conventional manufacturing methods without atmosphere control. It was found that the magnetic properties of SrO.2ZnO.$8Fe_{2}O_{3}$ are considerably improved on adding 1.5wt% $Na_{2}O$. Theoptimum condition of making magnet with suitable properties are as follows : chemical analysis composition : $Sr^{2+}_{0.852}Zn^{2+}_{1.721}Na^{+}_{0.301}Fe^{2+}_{0.723}Fe^{3+}_{15.703}O_{27}$ ; semisintering condition : $1300^{circ}C;{ imes};1h$ in air ; sintering condition : $1250^{circ}C;{ imes};0.5h;T_{c}=371^{circ}C,;H_{A}=1091.5kA/m,;K_{A}=2.13{ imes}10^{5}J/m^{3};and;n_{B}=31.8mu extrm{B}$