Abstract: An experimental study on co-pyrolysis of biomass and Pingshuo coal was performed using temperature programmed thermogravimetric analysis under atmospheric pressure in high purity nitrogen (99.999%). Sawdust and rice straw were chosen as biomass feedstocks. The final pyrolysis temperature was designed as 1 273 K and the heating rate was 10 K/min, and the mixture ratios of the biomass were 20%, 50% and 70% respectively. The results indicate that the initial temperature of volatile emission from Pingshuo coal and the temperature corresponding to the maximum pyrolysis conversion during co-pyrolysis vary with the ratio of biomass. Moreover, in co-pyrolysis there is difference between the experimental and calculated DTG curves. In addition, the method of Coats-Redfern was used to calculate the activation energy and frequency factor of pyrolysis for the coal and biomass. The results show that the activation energy and frequency factor change with the mixing ratio of the biomass, and it can be deduced that there exist the synergetic effects between the biomass and Pingshuo coal during their co-pyrolysis process.