Through monitoring a certain offshore wind power field’s two multi-pile-concrete 5 MW wind turbines’ towers vibration, its characteristics were obtained. From the analysis results of three years，monitoring data, multi-pile-concrete wind turbine towers revealed vibration characteristics that when wind turbines are in working states, cabin yaws to the wind cause towers’ frequent strong vibrations, these strong vibrations last for tens of seconds, their acceleration peaks can reach 10 m/s2, these strong vibrations appear for hundreds times per month; when wind turbines are in shutdown state, under action of small wind, tower vibration is steady and its acceleration peak is below 0.1 m/s2, under action of typhoon, tower vibration fluctuates largely and its acceleration peak can reach 10 m/s2, but the wind excites the second and third orders modal shapes of tower, the maximum acceleration of tower appears in its middle; within 3-year long monitoring period, the first 3 natural frequencies and damping ratios of tower unchanged. The monitoring results showed that towers of multi-pile-concrete wind turbines cause strong vibrations during typhoon and cabin yaws to the wind; so, besides typhoon, cabin yaws to the wind causing tower strong vibrations too often is also one of important factors to lead to fatigue damage of wind turbines’ towers. The study results provided a reference for design, safe monitoring in operation and damage diagnosis of this type wind turbines.