The Optimum Conditions of Preparing barium Ferrite from $BaCO_3$ and $Fe_2O_3$ are Sought for with electron microscope. At first to find the optimum sintering temperature, the mixture in 1 : 3 mole ratio. Sintered primarily at $700^{circ}C$ for an hour, is Sintered secondary at $960^{circ}C{pm}10,;1040^{circ}C{pm}10,;1120^{circ}C{pm}10,;1200^{circ}C{pm}10,;1250^{circ}C{pm}10,;1330^{circ}C{pm}10$, respectively for an hour. at the optimum temperature,abtained in this way. Sintering time is varied from 10 minutes to 120 minutes with 10 minutes intervals. Through the experiment, It is found that the optimum temperature of $1200{sim}1250^{circ}C$ and optimum time of half-one hour.