Abstract: Software FAST is used to study the dynamic response of a single tube steel tower and a steel-concrete combined tower of a2 MW wind turbine in the same wind farm under two typical working conditions-normal operation condition and emergency shut-down condition. The analysis results show that the displacement response at the top of the single steel tower is greater than that of the steelconcrete tower under both conditions,and under the normal operating condition,the acceleration response of the two towers is affected by frequency corresponding to the three and six times wind wheel rotation rate（3P,6P）. The dynamic response of the steeltower is obviously affected by the second-order vibration mode,and under the emergency shut-down condition,the vibration of the towers intensify,and the single steel tower is more sensitive than the steel-concrete tower,besides,the acceleration response in the fore-andaft direction of the two towers is mainly affected by the first-order vibration mode,while in the lateral direction the acceleration response of the towers is obviously affected by the second-order vibration mode.