Abstract: Vertically aligned carbon nanotube (VACNT) arrays were obtained using the floating catalyst method with cyclohexane as a carbon source. Results indicated that various factors, such as growth temperature, ferrocene feed rate, feed rate of the solution (ferrocene dissolved in cyclohexane), and composition of carrier gases, had a great effect on the VACNT array growth. A maximum growth rate of the VACNT array was obtained in a quartz tubular reactor with a diameter of 25mm when the growth temperature was 820℃, ferrocene feed rate 0.24mg/min, feed rate of the solution 0.12mL/min, and the flow rate of the H2/Ar (1∶15) carrier gas 640mL/min. A VACNT array with a height of 5.0mm was obtained with a large aspect ratio (>105) and a high purity (96.7%).