A　new　method　for　liquids　viscosity　measurement　is　proposed.　Magnetostrictive　sensor　is　employed　for　exciting　ultrasonic　torsional　guided　wave　in　a　metal　rod　probe.　The　guided　wave　energy　attenuation　coefficient　measurement　model　(attenuation　model)　and　velocity　measurement　model　(velocity　model)　are　numerically　analyzed.　The　advantages　of　attenuation　model　are　highlighted,　and　the　influence　of　its　three　parameters　including　operation　frequency,　probe　material　property　and　rod　diameter　are　investigated.　The　parameters　of　the　magnetostrictive　sensor-based　measurement　system　are　optimized　to　meet　the　requirements　of　precisely　measuring　the　liquids　with　a　given　viscosity　range.　The　attenuation　coefficient　of　a　optimal　sensing　system　must　be　equal　to　1　Np　or　in　the　range　of　0.5-5　Np.　The　viscosity　of　glycerine-water?　solutions　with　different　concentrations　(mass　fractions)　are　measured　based　on　attenuation　model.　The　experimental　results　are　well　agreed　with　the　results　obtained　from　traditional　measurement　method　and　theoretical　model　prediction　curves.　That　is,　the　proposed　method　can　be　applied　for　measuring　viscosity　of　liquids.　©　2014　Journal　of　Mechanical　Engineering.