针对“森林能否增雨、森林能否减少年径流量、调节枯水径流以及能否削减洪峰”等问题，综述了各种观点，分析了出现分歧的原因。作者认为森林对降水量的影响不大，森林植被的存在一般减少年径流量，而对调节枯水径流以及削减洪峰等的作用则因地带、因流域尺度而异。研究方法的局限性、研究对象的复杂性以及区域差异和尺度的影响，是导致争论的主要原因。正确评价森林的水文效应，应该注意地带性差异、尺度的影响以及不同森林的类型等。

 Some controversies on the forest hydrology were analyzed in this article． The controversies focus on(a)Can forests increase rainfall﹖(b)Can forests decrease annual runoff and regulate flows﹖(c）Can forests reduce floods﹖Many evidences and several viewpoints were listed．By the author＇s point， the effects of forests on precipitation are relatively small forests can reduce annual runoff compared with shorter vegetations and the effects of forest on dry season flow and peak flood mitigation can＇t be made the last word．The reasons that various and contradictive conclusions exist are due to the limitations of research methodology，the complexity of research object and the difference of region and scale． So， the difference of zonality，scale and species or type of forest should be considered when the effects of forest hydrology be evaluated．