Abstract: Fast pyrolysis and combustion properties of RDF (Refuse derived fuel) in thermobalance and tubular furnace at isothermal condition were investigated. Both pyrolysis and combustion of RDF have very fast reaction velocities. It takes 60 s～80 s to finish reaction from the time being heated, and about 20 s to complete reaction from weight loss occurred. The combustion profile of RDF is very similar to pyrolysis profile, only one weight loss region is found for both. The volatile matter of RDF firstly gives off and then burns, and the subsequent char is burnt simultaneously. The results show that the composition of RDF has effect on its pyrolysis and combustion reactivity. The RDF containing tyre has lower pyrolysis and combustion reaction velocities. There are 80%～90% of gas and liquid and 10%～20% of solid among pyrolysis product of RDF during fast pyrolysis at isothermal condition from 650 ℃ to 800?℃. The pyrolysis gas has higher heating value of about 20 kJ/m3 and RDF is suitable for pyrolysis.