Abstract: This article elaborated the importance of quantitative description of the microstructure of nanoparticles filled polymer composite. Summarized the domestic and foreign quantitative description method of the nanoparticles dispersed level in polymer composites, mainly includes the statistical method, the fractal theory, the group subTheory and other quantitative description method. Demonstrated with the computer graph technologys development, the microstructure of inorganic nanoparticles filled polymer composite could be quantitative described by the combination of digital image processing and the mathematical method.——’

Key words: polymer composite, quantitative description, statistical methods, the fractal theory, the sub-cluster theory