Abstract: There are a lot of phosphate resources in central Yunnan, at the same time, it is also the distribution area of Eupatoriumadenophorum and forest fire in Yunnan. It can provide a scientific basis for understanding the fire distribution characteristics in central Yunnan and reasonable choice combustible management and forest fire control methods by studied the relationship between the combustibility of Eupatoriumadenophorumstems and the soil available phosphorus content. And 23 batches of Eupatoriumadenophorumstems, which is from Anning city, Chengjiang county, Dongchuan district and so on, were selected as the research object, and determined the crude fat content, ash content, calorific value of the Eupatoriumadenophorumstems and the available phosphorus content of the root soil of Eupatoriumadenophorum. And calculated the combustibility index of Eupatoriumadenophorumstems by the crude fat content, ash content and calorific value, and analyzed the relationship between soil available phosphorus and crude fat content, ash content, calorific value, combustibility index. The research has shown that the ratios of crude fat content, calorific value and comprehensive index of combustibility positively correlated with soil available phosphorus content were 65.22%, 52.17%, and 56.52%, respectively, and the ratio of ash content negatively correlated with soil available phosphorus content was 60.87%. Andsoil available phosphorus content can increase the crude fat content and calorific value of Eupatoriumadenophorum stem to a certain extent, reduce its ash content, and increase the combustibility to a certain extent.

Key words: eupatoriumadenophorum, physicochemical property, soil available phosphorus, combustibility, comprehensive index