Abstract: The pyrolysis characteristics of walnut shell, coal and their blends sample at different heating rates (5-50 K/min) in a stream of N2 were studied using thermogravimetric analysis. The results showed that the pyrolysis speed increases with the heating rate for three samples increasing. It showed a good synergy during the co-pyrolysis of walnut shell and coal. The balance thermal decomposition temperature of walnut shell, coal and their blends was 568.9, 709.9 and 571.0 K, respectively. With the method of Coasts-Redfern, the pyrolysis process could be described by first-order global model for both of fast-pyrolysis and slow decomposition stage. The average activation energy was 50.6 and 17.3 kJ/mol for both pyrolysis stages of walnut shell, respectively. It was 21.1 kJ/mol for pyrolysis of lignite. But it decreased to 34.2 kJ/mol and 14.5 kJ/mol for both pyrolysis stages of blends of walnut shell/coal, respectively.