Abstract: In ancient China, grievous soil erosion resulted from forest destruction damaged the society seriously. The laboring people accumulated much experiences and valid measures in the practice of soil and water conservation, especially using forest and grass. The main theories included that mountains and rivers were root of a country, forests could firm soil and defend disasters, and the key of taming rivers was to manage mountains. The measures contained that forbidding mountain to protect forests, forestation on barren hills, planting tree to strengthen dikes, planting grass to hold silt, etc. Lessons were as follows: theory was divorced from practice, the stress of theories are flood control rather than mountain management, and engineer measures was regarded as the more important than the vegetation.