Uniform and well-defined lanthanide hydroxide and oxide micro/nanorods Ln(OH)_3(Ln=La, Pr, Sm, Eu, Gd, Er) and Gd(OH)_3:Eu~(3+), Gd_2O_3:Eu~(3+) were successfully synthesized through a green and facile hydrothermal method. Tetrabutylammonium hydroxide(TBAH) and lanthanide nitrides were used as the hydrothermal precursors without the addition of any templates/surfactants. The products were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM) and photoluminescence(PL) spectra. The result demonstrated that lanthanide hydroxide micro/nanorods with 20–80 nm in diameter and 50–450 in length were obtained. The size of the Ln(OH)_3(Ln=La, Pr, Sm, Eu, Gd, Er) rods increased with the increase of the atomic number. The size of the Gd(OH)_3:Eu~(3+) rods decreased with the increase of p H value by modulating the amount of the TBAH solution. The as-formed product via the hydrothermal process, Gd(OH)_3:Eu~(3+), could be transformed to Gd_2O_3:Eu~(3+) with the same morphology and a slight shrinking in size after a post annealing process. It is a facial method to synthesize photoluminescent nanomaterial of Gd_2O_3:Eu~(3+). The Gd_2O_3:Eu~(3+) microrods exhibited strong red emission corresponding to ~5D)0→~7F_2 transition(610 nm) of Eu~(3+) under UV light excitation(257 nm). Uniform and well-defined lanthanide hydroxide and oxide micro / nanorods Ln (OH) _3 (Ln = La, Pr, Sm, Eu, Gd, Er) and Gd (OH) _3: Eu ~ (3+), Gd_2O_3: Eu ~ (3+) were successfully synthesized through a green and facile hydrothermal method. Tetrabutylammonium hydroxide (TBAH) and lanthanide nitrides were used as the hydrothermal precursors without the addition of any templates / surfactants. The products were characterized by X-ray diffraction (XRD) The resulting form that lanthanide hydroxide micro / nanorods with 20-80 nm in diameter and 50- The size of the Ln (OH) _3 (Ln = La, Pr, Sm, Eu, Gd, Er) rods increased with the increase of the atomic number. The size of the Gd (OH) _3: Eu ~ (3+) rods decreased with the increase of p H value by modulating the amount of the TBAH solution. The as-formed product via the hydrothe Gd (OH) _3: Eu ~ (3+) could be transformed to Gd_2O_3: Eu ~ (3+) with the same morphology and a slight shrink in size after a post annealing process. It is a facial method to The Gd 2 O 3: Eu 3+ microrods showed strong red emission corresponding to ~ 5D) 0 → ~ 7F 2 transition (610 nm) of Eu 3+ under UV light excitation (257 nm).