Ultrasonic　tomography　(UT)　is　an　available　method　for　processing　monitoring.　In　this　study,　a　novel　dual-excitation　method　(DEM)　for　ultrasonic　tomography　for　improving　imaging　quality　is　proposed.　The　DEM　was　defined　and　explained　first　in　the　study.　Two　typical　bubble　flow　patterns　were　established　to　evaluate　the　effectiveness　of　the　method　using　linear　back　projection　(LBP)　and　fan-shaped　LBP　(FLBP).　In　order　to　quantitatively　analyze　the　imaging　quality,　the　image　correlation　coefficient　(ICC)　and　the　position　error　(PE)　were　chosen　as　two　evaluation　indexes.　For　two　different　bubble　flow　patterns　with　a　16-transducer　UT　system,　the　ICCs　were　improved　by　13%　and　15%,　whereas　the　PEs　were　reduced　by　19%　and　4%　by　the　DEM,　respectively.　Then,　the　influence　of　the　noise　was　discussed.　Thereafter,　two　postimaging　methods,　such　as　the　sum-imaging　method　(SIM)　and　the　multiplication-imaging　method　(MIM),　were　proposed　and　applied　to　further　enhance　the　imaging　quality.　Compared　with　the　original　imaging　quality,　the　PEs　were　reduced　by　28%　and　6%　for　the　two　different　bubble　flow　patterns.　The　results　indicated　that　the　DEM　could　significantly　improve　the　imaging　quality,　especially　when　MIM　is　assisted　for　image　reconstruction.　©　1963-2012　IEEE.