Magnetic properties of La doped M-type barium ferrites are studied. The samples are prepared by the standard solid state reaction method. The influences of La3+ on structures and magnetic properties of barium ferrites (Ba1-xLaxFe12019) are investigated. Single- phase M-type barium ferrites with chemical composition of Ba1-xLaxFe12O19 (x = 0.0~0.6) are formed by sintering at 1100- 1175 ℃ in air. Scanning electron microscopy (SEM) reveals that the La doping has no effect on the structure of barium ferrite. Vibrating sample magnetometer (VSM) shows that with the valaue of x increasing, the saturation magnetization (Ms) increases, reaching a maximum at x = 0.2 and then decreases and the coercivity of the sample increases continuously. The value of Ms reaches a maximum value of 62.8 emu/g at x = 0.2 and 1175 ℃, and the He reaches a maximum value of 3911.5 Oe at x = 0.6 and 1125℃.%用固相法制备了镧掺杂M型钡铁氧体（Ba1--xLaxFel2O19，x=0．0-0．6），针对不同取代量与不同温度的烧结，研究取代量和温度对钡铁氧体微结构和磁性能的影响．在烧结温度为1100-1175℃，当X=0．0-0．6时，样品主要有单一的六角M型钡铁氧体相构成．SEM表明，La离子的加入不会影响钡铁氧体微观形貌．在磁性能方面，随着La离子的增加，钡铁氧体的饱和磁化强度先增加后减小，矫顽力逐渐增加．在同一取代量下，钡铁氧体的饱和磁化强度随烧结温度升高呈现上升趋势，矫顽力随着烧结温度的升高而降低．饱和磁化强度在x=0．2，烧结温度1175℃时达到最大值62．8emu／g，矫顽力在x=0．6，烧结温度1125℃时达到最大值3911．5Oe．
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