Abstract: The forest fire in dry-hot valleys in Liangshan area is very serious,which has certain seasonal, and is difficult to be put out. This paper deals with the causes of forest fires in this area by field investigation, literature consultation, qualitative analysis, etc. And it is concluded that forest fires in this region are mainly caused by human factors. And therefore such control measures as publicity education, management, regulation, engineering and so on are put forward for forest fire prevention.