Abstract: According to forestry industry development in Jiangsu, the inner relevance and the relationship among the first, second and third forestry industry were investigated with the industrial relevance analysis method. The result showed that relevance of the second and third industry was stronger than with the first in the forestry industry and relevance of lumber harvesting, wood processing, forestry tourism and leisure industry was the strongest in there three forestry industries respectively. We put forward the corresponding suggestions for the optimization of industry structure according to every industry relevance effect.