Ultra-fine particles of La(1-x)A(x)MnO3 (A = Ba-'(2+) Sr2+ or Ca2+, x less than or equal to 0.3) with high surface area and single perovskite structure were prepared by a Na2CO3-NaOH coprecipitation method. The so-prepared ultra-fine particles exhibited high catalytic activity for CH4 total oxidation. The ultra-fine particles of La1-xBaxMnO3 prepared with this method were thermally more stable than LaMnO3 and La1-xSrxMnO3, and its surface areas were close to 20 m(2)/g after sintering at 1000degreesC for 2 h. La1-xBaxMnO3 exhibited higher activity for methane total oxidation than La1-xSrxMnO3, and among the La1-xBaxMnO3 series La0.8Ba0.2MnO3 showed highest activity.