In　this　paper,　the　transient　absorbance　spectra　and　kinetics　characteristics　of　DBP　are　studied　in　266nm　laser　flash　photolysis　with　three　different　mixed　solvents.　The　transient　species,　assigned　to　DBP　excited　triplet,　with　maximum　absorption　at　300nm　were　observed　in　deoxidation　system　meanwhile　its　decay　process　accelerated　obviously　in　O-2-statured　system.　By　changing　the　concentration　of　DBP　a　series　of　observed　decay　rate　constants　were　obtained　and　the　self-quenching　rate　constants　of　DBP　excited　triplet　were　determined　to　be　4.5x10(7),　3.0x10(7)　and　2.2x10(7)　mol(-1)　s(-1)　L　for　ethanol/water,　methanol/water　and　acetonitrile/water　systems　and　self-decay　rate　constants　to　be　0.96x10(5)　s(-1),　1.25x10(5)　s(-1)　and　1.33x10(5)　s(-1),　respectively.　It　revealed　that　the　properties　of　DBP　excited　triplet　have　some　relationship　with　the　dielectric　constants　of　solvents.