[Objective] Forest fires cause heavy loss to forest resources and society and economy and directly imperil the sustainable development of forestry and national ecological security. Study on the temporal and spatial distribution of forest fires and their risk analyses were helpful to understand the law of forest fires, to provide a scientific basis for forecasting, preventing forest fires and establishing different fiscal subsidy and insurance policies. The study is important to promote forest sustainable development and to maintain the national ecological safety. [Method] In order to find out the basic situation of forest fires in China, the forest fire temporal and spatial distribution characteristics and risk analysis were studied based on the yearbook data from 1950 to 2010 and by means of principal component analysis, cluster analysis and information diffusion theory. The temporal and spatial characteristics of forest fires in each province were comprehensively analyzed conducted, and further evaluated and classified by innovatively combining the disaster index. The fire risk level was quantitatively analyzed to provide scientific basis for forest fire prediction and prevention, to establish the fiscal subsidy policy, and to provide the basic support to forest safety risk prevention and risk decision. [Result] 1) nnual average fire number was 12 683 times and burned an area of 674 800 hm~2 per year from 1950 to 2010, and the annual average fire number and the burned area showed a downward trend. Average annual fire-caused disastrous area was 79 500 hm~2 and showed an increase trend overall from 1988 to 2010; Annual average stand volume loss was 1. 675 million m~3 from 1988 to 2010 without obvious year-to-year variations; Annual average casualties was 214 people from 1988 to 2010 and showed overall a downward trend. 2) Human-caused fires accounted for more than 80% of the identified fires. Burning grass on waster land and burning charcoal were one of the main productive causes (38. 47%), and sacrificial fires at graves were the main non-productive (19. 92%). 3) Fire number in Eastern China and Southwestern China was significantly more than the other regions in China, while the burned area was significantly larger in Northeastern China than that in the other regions in China. 4) According to parameters of the general and large fire number, the major and catastrophic fire number, the burned area, the disastrous area, the stand volume loss, the young stand loss, and the casualties, this paper evaluated the fire situation in 31 provinces (The data of Hongkong, Macau and Taiwan are not included) using PCA and ranked them. Then the cluster analysis was conducted with comprehensive scores obtained by PCA. The 31 provinces were divided into 5 types: serious, heavy, moderate, general and light, and Hunan was most serious and followed by Heilongjiang, Guizhou and Yunnan. 5) With the information diffusion theory, the occurrence probability of general and large fire number in 3 000-9 000 was (>0. 482 4), the major and catastrophic fire number in 0-30 was (>0. 430 2) and the disastrous area under 150 000 hm~2 was (>0. 407 2). [Conclusion] Frequent forest fires, large area in China were closely linked with climate change. The main reason causing the forest fire was man-made fire, and we must strictly control and manage field fire sources, and regulated productive and life fire-used behavior. Forest fires were with obvious regional feature and fire risk pressure was high in China. According to the results, it is suggested that it is important to strengthen the propaganda and education, take scientific measures for preventing, predicting and monitoring forest fires, establish reasonable fiscal subsidies and forest fire insurance policy, and maintain the forest health and national ecological security based on the accurate grasp of the national forest fires distribution and risk.