The properties of akaganeite (β-FeOOH) are affected by the coexisting ions and can be changed by doping various ions. Tin doped β-FeOOH nanorods were prepared using β-FeOOH nanorods as the precursor under hydrothermal conditions. The effect of tin ions on the thermal property of β-FeOOH was investigated. The doping of tin ions was confirmed by X-ray powder diffraction, energy dispersive spectroscopy, and atomic emission spectrometer analysis. The adsorption of tin ions on the surface of β-FeOOH could prevent the transformation from β-FeOOH nanorods to α-Fe2O3 in solution. Thermogravimetric analysis and differential thermal analysis showed they have different thermal decomposition temperatures. β-FeOOH nanorods were transformed into α-Fe2O3 particles at 400 °C. While tin doped β-FeOOH nanorods should be heated to 600 °C. Tin doped β-FeOOH nanorods showed higher thermal stability than that of β-FeOOH nanorods. The presence of tin ions is favor of the formation of rod like shape.