Using the methods of combining theory and practice,combining qualitative and quantitative analysis,combining comparison with demonstration,on the basis of introducing market mechanism,the technology extension model of afforestation projects in Yunnan including risk control system,implementation system and evaluation criterion system was constructed.

After discussion on Chinese traditional patterns of agricultural technology,it s concluded that the key caused inefficiency to agricultural technology extension is ignorance of gender under the female tendency of agricultural production.

In order to increasing the application of science and technology in forestation, as soon as beginning the project, the extension of science and technology was attached importance to, 6 items important scientific and technological achievements in Yunnan or other provinces in our country were extended successively, test forest, demonstration forest, environmental protection monitor plot of the main.

With analysis,this paper revealed that the Sci-tech extension for agriculture integrated development has the basic characteristics of comprehension,dominance,popularity and application.

How to commercia-lize the scientific and technological progenies of forestry in Hunan,the anther considers,strengthening the scientific and technological extension of forestry in Hunan is a important tache.

A Discussion on the Social Property of Promoting Science and Technology in Countryside;