Due to the outstanding physicochemical properties, carbon nanotubes (CNTs) have been widely studied and applied in the nanoscience and nanotechnology fields. Herein, Fe-based catalysts were prepared by the impregnation method using Al2O3, SiO2, ZrO2, TiO2 and SnO2 supports, and used for CNTs synthesis from n-hexane under different reaction time and temperature. It was found that the metal-support interaction and Fe2O3 particle size of Fe-based catalysts regulated CNTs growth. The moderate metal-support interaction of Fe-Al2O3, Fe-SiO2 and Fe-ZrO2 was suitable for CNTs synthesis: Fe-Al2O3 and Fe-SiO2 produced 383.2-494.6 mg/g CNTs with a diameter of 23.3-26.4 nm; Fe-ZrO2 exhibited a lower CNTs yield of 141.8 mg/g with a wider diameter of 49.3 nm. Fe-TiO2 metal-support interaction was too strong and SnO2 support exhibited strong reducibility, both of which inhibited CNTs synthesis. Since Fe2O3 particle would stepwise participate in CNTs synthesis in the activity order, it led to the increased quantity while the decreased formation rate of CNTs with the prolonged reaction time, which can be compensated by increasing the reaction temperature.