Abstract: As one of the four biggest forest shelterbelt programs in the world, the Three-North Forest Shelterbelt Program didn't achieve due defending purpose. As for the reasons, there are conflictions with Chinese climate pattern and population pressure, ecological principles and market rules since the very beginning of this program. New situation of Chinese desertification demands transformation of the Three-North Forest Shelterbelt Program，which should solve the conflictions firstly. And several suggestions，such as satisfying water demand of afforestation, peristing in diversification route and market direction and establishing ecological compensation mechanism, were put forward at last.

Key words: Three-North Forest Shelterbelt Program, desertification, defending efficiency

摘要： 作为世界4大防护林体系之一的“中国三北防护林体系工程”，经过20多年的建设，却没有达到预期的防护目的。究其原因，作者认为三北防护林体系工程从规划建设伊始，就存在与中国气候格局和人口压力、生态学基本原理、社会主义市场规律之间的三大矛盾冲突。新形势下的荒漠化防治要求三北防护林体系工程必须发生相应的转型，这种转型应以解决三大矛盾冲突入手。最后，提出了造林必须满足林木生长对水分的需要、坚持多样化复合型的建设思路、坚持以市场为导向与建立生态补偿机制等几项建议。

关键词: 三北防护林体系工程, 荒漠化, 防护效益