In this paper, we report the synthesis of Fe-filled carbon nanotube arrays by floating catalyst chemical vapor deposition, which employed ferrocene as both catalyst precursor for carbon nanotube growth and the iron source for iron filling. We obtained Fe-filled carbon nanotube arrays perpendicular to the surface of the quartz substrates by floating catalyst chemical vapor deposition. We also conducted controlled experiments at different temperatures. Our results indicated that a higher synthesis temperature is needed for synthesizing Fe-filled carbon nanotube arrays. Magnetic property measurements revealed that the Fe-filled carbon nanotubes exhibited a high average coercivity of about 589.97G.