A serious fire accident event occurred and spread in camphor wood fore st in Honggolj, Hulun Buir, Inner Mongolia in May 16, 2006. The weather conditio ns of the event are analyzed synthetically based on the meteorological data, the meteorological satellite and GIS data. The result indicates that (1) the high t emperature and less rainfall with serious droughty and gale are the important co nditions for the event occurrence; (2) The calculated synthetic indexes of fores t combustibility are 395 and 423, that build a fire for lightning stroke accordi ng with practical situation; (3) The spread speed in fire field was 137.2hm2/h under forcefour wind with the temperature in the range of 5.9—6.5℃ ; and the speed was 173.2hm2/h under forcefive wind with temperature 7.6～8.4℃. (4) That speed is usually 137～173 hm2/h under the varying range of force 4 5 wind and 5.9～8.4℃ temperature.