Decentralized　control　by　low-order　dynamic　compensators　for　damping　the　low-frequency　oscillations　in　power　system　was　proposed　in　this　paper.　The　compensators　located　in　different　places　were　designed　simultaneously　to　ensure　the　totally　best　damping　effect　for　all　the　electromechanical　oscillation　modes.　Local　measurable　signals　and　some　important　remote　signals　provided　by　the　wide　area　measurement　system　(WAMS)　were　both　adopted　as　compensator　input　to　increase　the　damping　of　local　and　inter-area　oscillations.　Multiple　operating　conditions　were　considered　simultaneously　to　design　controllers.　The　regional　pole　placement　was　used　to　make　the　close-loop　system　get　satisfactory　dynamic　performance.　The　design　problem　was　formulated　as　a　non-smooth　optimization　problem,　and　gradient　sampling　algorithm　was　employed　to　solve　it.　The　simulation　results　of　two　systems　show　that　notable　effect　for　damping　the　low-frequency　oscillations　can　be　obtained　by　designed　controllers,　which　excelled　power　system　stabilizer　(PSS).