Optical　systems　have　been　extensively　studied　for　target　recognition　in　a　turbid　medium　because　of　its　promising　applications　in　many　fields　such　as　driver　assistant　system.　Several　recent　studies　have　demonstrated　that　relevant　information　of　the　turbid　medium　including　the　hidden　object　in　the　medium　can　be　derived　by　analyzing　the　polarization　state　of　diffusely　backscattered　light　of　the　sample.　In　this　paper　Stokes/Mueller　formula　was　introduced　to　investigate　polarized　light　transportation　in　a　turbid　medium　such　as　atmosphere;　Mie　scattering　theory　was　applied　to　calculate　the　scattering　property　of　polarized　light;　Monte　Carlo　method　was　used　to　compute　backscattered　polarization　patterns　from　a　turbid　medium　containing　hidden　object.　Results　showed　that　the　backscattered　polarization　patterns　are　strongly　influenced　by　optical　parameters　of　the　medium.　The　two-dimensional　distribution　of　degree　of　polarization　(DOP)　calculated　from　backscattered　Mueller　matrix　can　well　discriminate　different　objects　within　limited　distance.　For　applications　in　driver　assistant　system,　the　effective　recognition　distance　in　a　foggy　weather　was　also　calculated;　and　results　could　be　several　times　of　visibility　distance.