Forestry functions of Danzhai County are introduced from the aspects of physical production value, social service value and ecological service value. Quantitative research on monetary value of the functions is conducted by using the Replacement Cost Method (RCM), Classification Valuation Method (CVM) and Travel Cost Method (TCM). Result shows that the value of forestry production is 19712.6 thousand yuan, the value of flood control and water conservation is 111000 thousand yuan, which is 5.63 times of forestry production value. Besides, the value of soil conservation and yield increase is 160101.5 thousand yuan, which is 8.12 times of the value of forestry production; the value of carbon fixation and oxygen release and air purification is 11 26624.1 thousand yuan, 57.15 times of the value of forestry production; and the value of the employment and income increase, and the landscape and recreation is 5380 thousand yuan, which is 0.27 times of the value of forestry production. Due to the important external role of the forestry, government should take into account the multifunction of forestry when making policies in order to promote the effective development of forestry and the sustainable development of agriculture.