A　LC　smith　matching　method　for　capacitive　micromachined　ultrasonic　transducers　(CMUTs)　was　presented　for　biochemical　application.　We　completed　the　fabrication　of　CMUTs　based　on　the　direct　bonding　technology.　A　modified　Butterworth　van-Dyke　(BvD)　model　with　lumped　elements　for　functionalized　CMUTs　were　proposed　to　fit　the　electrical　impedance　and　phase　of　CMUTs,　which　were　accurately　measured　by　the　impedance　analyzer.　The　series　and　parallel　frequencies　of　CMUTs　were　obtained.　It　is　difficult　for　the　functionalized　CMUTs　to　achieve　the　transmission　from　capacitive　reactance　to　inductive　reactance　at　relatively　low　DC　voltage.　And　the　proposed　LC　matching　network　can　optimize　the　properties　of　impedance,　phase,　resistance,　especially　reactance　near　the　resonant　region.　This　is　important　for　the　real-　time　oscillator　design,　which　needs　strict　condition　for　the　Barkhausen　stability　criterion　of　gain　and　phase.