In this article, the bed agglomeration in the straw-fired fluidized bed was studied. The influence of fluidization velocity and bed temperature on the fluidization time was investigated. The effect of running parameters on the fluidization recovery, after the defluidization had occurred, was studied. Results showed that the fluidization time decreased with the increase of the bed temperature or with the decrease of the fluidization velocity. Fluidization can be recovered only by means of decreasing the bed temperature. The molten materials in the agglomerates were formed by the fuel particles. An agglomeration mechanism was proposed according to experimental findings.