Abstract: The representativeness of measurement made by wind masts is one of the most important factors for the wind resource evaluation accuracy. After literature review，it is found out that current representativeness analyses of wind masts are mainly qualitative analyses. Proposing the concept of theoretical reduction coefficient and taking it as the measurement standard for wind mast representativeness， quantitative analysis on wind mast representativeness can be carried out innovatively. In a practical case，the theoretical reduction coefficient at each wind turbine position was calculated by comparing the evaluation value of a wind farm in the design stage with the actual power generation during its operation. After the theoretical reduction coefficient analysis， the main factors affecting the representativeness were considered as the distance and the elevation difference between the wind mast and each wind turbine.The linear fitting formula of theoretical reduction coefficient and the distance between the wind mast and each wind turbine indicated that there was no obvious correlation between the two factors， while according to the linear fitting formula of the representativeness of the wind mast and the elevation difference， there was a clear negative correlation between the two factors. In the current standard， the wind mast with elevation difference less than 50 m is of decent representativeness.However，according to the practical data in the case， the wind mast with elevation difference less than 30 m is of proper representativeness.

Key words: correction of representative year, theoretical reduction coefficient, wind mast, wind turbine position, elevation difference, power generation, linear fitting formula