Whether forest fires in Yunnan increase or not under the background of global warming has become a hot issue focused by the government, common people, and scientists. The key to understand the relationship between climate changes and forest fires is to understand forest fire history under natural conditions during the geological times. We propose to conduct analyses of pollen and charcoal on samples from lake surfaces and cores in Yunnan to reveal this relationship. We will collect surface samples from lakes and ponds for pollen and charcoal analysis to establish modern pollen-climate and charcoal-fire databases, and then build modern pollen-climate transfer functions and determine the quantitative and semi-quantitative relationship between charcoals and forest fires including fire frequency and intensity. By applying modern transfer functions to fossil pollen records with precise dating from two lakes of Yunnan, we will establish two high resolution Holocene climate sequences, which can be used for regional and global comparisons. By applying the modern charcoal-fire relationship to charcoal records from two lakes, we will reconstruct regional forest fire histories during the Holocene. Based on the reconstructed vegetation, climate and regional forest fire histories, we will examine forest fire frequency and intensity under natural conditions and intensified human activities, determine climatic conditions and vegetation types relevant to forest fires, and finally discuss the role of human activities in regional forest fire histories of Yunnan. This project will provide scientific basis for comprehensively understanding of regional forest fires, the ecological environment protection, and the forest fire prevention and control in Yunnan.