resulted from the glass-transition of natural binders. In this research, the formation temperature was more than 70 C due to particle rubs. Liu et al. found that there was an a-transition (a1) peaking due to the glasserubber transition of lignin at about 65 C (Outer of bamboo), 83 C (Middle of bamboo), and 75 C (Inner of bamboo), respectively [26]. Stelte et al. found that the glass-tran- sition of softening lignin from wheat straw was about 53 C [27]. Lignin can be classified into three major groups based on the chemical structure of their monomer units, which are softwood lignin, hardwood lignin and grass lignin [28]. The lignin of rice straw and wheat straw can be similar and the glass-transition of rice straw can occur at a lower temperature than that of bamboo. This causes a weaker mechanical strength of bamboo pellets than that of pellets from mixture and rice straw.