The surface oxygen distribution, the active oxygen species for CO on the perovskite-type catalyst La1-xSrxCo1-xMnxO3 and its catalytic oxidation activity with CO as probe were investigated by means of XRD, TPD and XPS in a continuous flow microreactor. Results showed that different adsorbed oxygen species and lattice oxygen were distributed on the catalyst surface. Meanwhile, the surface lattice oxygen of the oxides was reacting in the course of CO oxidation. This leads to the conclusion that, when x=0.6, the catalyst shows the best oxidative activity and lower starting temperature.