Abstract: Yttrium hydroxide nanotubes were synthesized by hydrothermal method using Y₂O₃ as raw materials. And then yttrium hydroxide nanotubes were characterized by X-ray diffraction （XRD）,scan electron microscope （SEM）, energy-dispersive X-ray spectroscope (EDS) and thermogravimetry-differential thermal analysis（TG-DTA）to investigate the phase, morphology, composition and heat stability of the products. Effects of reaction temperature and hydrothermal time on the formation of hydroxide yttrium nanotubes were studied. The results indicate that the optimal reaction conditions of hydroxide yttrium nanotubes are as follows: T=220℃, pH=11-12 and t=24h. The formation mechanism of hydroxide yttrium nanotubes is suggested to be twostep process，the initiative production of yttrium precursor and the successional achievement of hydroxide yttrium nanotubes.

Key words: hydrothermal synthesis, yttrium hydroxide, nanotubes