运用４种方法分别测定了３种林型的蒸散量， 分析了４种方法的优缺点及其适用范围。在静风条件下或人力不足时，用能量平衡法能获得满意的结果；在人力允许而仪器不足时， 用实测法可获得准确的数据；空气动力学法不适用于静风天气，实际工作中可根据人力、物力和天气条件选用上述３种方法中的一种与彭门公式法配合运用， 则能较准确地测定不同林型的日、季、年蒸散量。本文用能量平衡法和彭门公式配合，计算了３种林型的年蒸散量，其中阔叶林的年蒸散量为１ １２５７ ｍ ｍ ， 杉木林为１ １０５０ ｍ ｍ ， 黄山松林为１ ０７４２ ｍ ｍ 。结果表明， 在亚热带北缘山区以阔叶林的蒸散量最大， 理水效能最佳 The evapotranspiration of three forest types were measured by four methods. The advantages and disadvantages of the four methods and their applicable scope were analyzed. In the case of static wind conditions or lack of manpower, the energy balance method can get satisfactory results in the human allowable and insufficient instruments, the actual measurement can get accurate data; aerodynamic method does not apply to the wind, the actual work According to human, material and weather conditions, the selection of one of the above three methods combined with Pengmen formula method can accurately measure the daily, seasonal and annual evapotranspiration of different forest types. In this paper, the annual evapotranspiration of three types of forest was calculated by energy balance method and Pengmen formula. The annual evapotranspiration of broad-leaved forest was 1 1257 m m and that of Chinese fir forest was 1 1050 m m. Is 1 074  2 m m. The results showed that the deciduous forest in the northern subtropical mountains had the largest amount of evapotranspiration and the best water management efficiency