In this paper，two polypropylene（PP）/carbon black（CB） films containing 2.2% and 3.3% of carbon black（CB） contents were prepared by melt blending-masterbatch dilution method assisted with high efficiency dynamic mixer.Based on scanning electron microscopy（SEM） and optical microscopy（OM） images，the image analysis software，Image J，was firstly used to quantitatively characterize the dispersion and distribution of CB particles.The results of SEM analysis showed that the average area of CB particles was 0220 μm2 and the area distribution strictly conforms to exponent decay distribution.The results of OM analysis indicated that a small amount of CB agglomerates appeared when the CB content reached up to 3.3%.The dispersion index（D） of films with 2.2% and 3.3% of CB were 0.75 and 0.5，respectively，which indicated that high CB content was not conducive to CB dispersion.Furthermore，the average area of particles（0.209 μm2） in film with low CB content was less than that（0.220 μm2） in film with high CB content.However，their area distributions showed a great similarity and they both conformed to exponent decay distribution strictly.The results of OM were consistent with that of SEM.The image analysis software，Image J，can convert qualitative information into quantitative information and characterize comprehensively the dispersion of CB particles in polymeric matrix by combination with the dispersion indexes.