Observation and research of forest fuel are important for the prediction of fire danger class, with the data of 8 stations in Changbai mountain (6 measuring points per station), the variations of fuel moisture were analyzed. It was found that the average fuel moisture in Changbai mountain under forest was 40%, and in most observation dates, it was not easy to burn for the fuel moisture there. Highly flammable condition appeared only one station, easy-to-burn days occupied 12% of the total days. The fuel moisture of the whole Changbai mountain under forest and the fuel moisture of the same measuring point and of different stations had a good consistency in variation. Analysis of fuel moisture and meteorological element data showed that there was an obvious link between fuel moisture and daily maximum temperature, evaporation capacity, sunshine duration. And there was good correlation between fuel moisture and cumulative precipitation 3 days before observation.