Due to the complex structure of char particle

most of researchers can only describe particles qualitatively or in a specific aspect.Fractal theory is a powerful tool to describe complex phenomena comprehensively and precisely.In this paper

a new method which is based on fractal BET model with the help of non-linear least square is introduced to calculate fractal dimension.Multilayer adsorption theory was combined with the corrected Kelvin equation to analyze nitrogen adsorption/desorption data to get the fractal dimension which represented whole pore characteristics of the measurement range.Meanwhile

this method regressed the layers during the adsorption process.The analysis result showed that not only calculated fractal dimension could represent particle pore network satisfactorily but also calculated adsorption layers could be explained by the multilayer adsorption theory.This method has both satisfying mathematical result and physical significance.This method was used to calculate the fractal dimension of rice husk char particles prepared by high speed pyrolysis.