Abstract: Diethylenetriaminepentaacetic acid-functionalized multi-wall carbon nanotubes (MWCNT-DTPA) were labeled by 99mTc and intravenously administered to rabbits, the radioactivity in different organs was scanned by single photon emission computed tomography and a well-type γ counter. Results showed that the administered MWCNT-DTPA-99mTc was mainly distributed in heart, liver, spleen and kidney. Centrifugate from urine was subjected to transmission electron microscopy analysis which showed that MWCNTs could be excreted through the urinary system.