Abstract: A new method was developed for measuring the reactivity of char from biomass pyrolysis. The reactivities of chars from rapid pyrolysis in a free-fall reactor and slow pyrolysis in a steel jar were studied at 800℃. Similar experiments were carried out with charcoal, petroleum coke and metallurgic coke for comparative study. The relationship between reactivity and surface area of the char was also investigated. Results showed that the new method is simple and works well. The reactivities of the char from biomass pyrolysis are a little lower than that of charcoal, but mostly higher than those of petroleum coke and metallurgic coke. The chars are suitable for gasification and combustion. Surface area of the chars increase slightly with the increase of pyrolysis temperature. Both characteristics of raw material and heating rate affect the reactivity and surface area of the char.