The effect of the heating rates and the existence of a Ni-catalyst on the thermogravimetric characteristics of wheat straw were investigated by thermogravimetry and gas chromatography-mass spectrometry. The weight loss of wheat straw was not markedly influenced by the heating rates, over a temperature range from 220.6 to 391.2 °C, although, to obtain the same weight loss, the corresponding temperature was increased and the heating rates were enhanced. The thermogravimetric kinetic parameters of

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... wheat straw were calculated both without catalyst and with 0.5% Ni-catalyst, by the method of Kissinger; the apparent activation energy values of wheat straw were of 93.92 and 119.80 KJ·mol-1 , and the frequency factors lnA were of 17.82 and 23.02 min-1 , respectively. The weight loss of wheat straw was not markedly influenced by the Ni-catalyst, while pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) evidenced that, at 800 °C, the presence of the catalyst influenced the peak intensities derived from cellulose, hemicellulose and lignin. It was concluded that the Ni-catalyst favors a more catalytic effect on wheat straw lignin, that is, the total value of the peak area from phenolic compounds and vanillin was higher than that from furfural and levoglucosan.