Dissimilar　solids　fluidization　is　a　widely　encountered　phenomenon　in　many　industrial　processes　in　which　the　inevitable　mixing　or　segregation　phenomenon　is　very　important　for　reactor　design　and　operation.　In　this　paper,　a　new　quantitative　measurement　method　for　mixing　and　segregation　of　binary　mixtures　in　bubbling　fluidized　bed　was　developed　based　on　capacitance　probe.　Verification　experimental　results　showed　that　capacitance　probe　is　a　reasonable　method　for　mixing　and　segregation　of　binary　mixtures.　A　linear　relationship　between　probe　signal　and　fraction　distribution　of　solids　in　binary　mixtures　was　found.　Transient　and　steady　fluidization　experiments　of　binary　mixtures　with　almost　equal　size　but　different　densities　were　conducted.　In　transient　fluidization　experiments,　the　real-time　mixing　process　of　initially　totally　segregated　binary　solids　and　finally　reached　steady　mixing　state　were　acquired.　The　mechanisms　of　mixing　processes　in　binary　mixtures　fluidized　bed　with　different　density　ratios　were　analyzed.　In　steady　fluidization　experiments,　the　distribution　of　mixing　information　in　bubbling　fluidized　bed　was　acquired　and　the　results　showed　reasonably　good　agreement　with　theories　in　the　literature.　In　summary,　capacitance　probe　proved　to　be　a　useful　method　in　mixing　or　segregation　of　binary　mixtures　fluidization.　(C)　2017　Elsevier　B.V.　All　rights　reserved.