La(1-x)Sr(x)MnO3 (x = 0, 0.2, 0.5, 0.8) nanoparticles were synthesized and their chemiluminescence (CL) and catalytic properties of CO oxidation were determined. We mainly investigated the influences of filter band length, flow rate of gas, test temperature, catalyst compositions, and particle size on CL intensities and catalytic activities of the catalysts. The catalysts were characterized by means of XRD, TEM, N2 adsorption isotherm, CO-TPD, and O2-TPD, etc. It was found that the strong CL response signals occurred over these perovskites nanoparticles; and that CL properties of the catalysts were well correlated with the reaction activities. These nanoparticles can be used to fabricate a stable gas detector due to a high activity and stability of perovskite structure. CL mode could be a rapid and effective method for the selection of new catalysts from thousands of materials, as well as for the detection of environmental deleterious gases.