Scanning electron microscopy (SEM) was used to study the structure and morphology of partly compatible binary blends of polypropylene with poly(cis-butadiene) rubber. The SEM images were transformed by digital image process software designed by Our group, and binarized images were obtained. The size (mean diameters d(p) and characteristic lengths L) of phases was calculated using binarized images. Small-angle light scattering was employed to study the structure and morphology of phases in the blends. The structural parameters, including correlation distance a(c), average chord lengths (l) over bar, and mean diameter D, to describe the structure and morphology of phases in binary blends, were calculated based on the corresponding theory. The variation of correlation distance a(c), average chord length (l) over bar, and mean diameter D-S were the same as that of mean diameters d(p) and characteristic length L. At the same time, the distribution of sizes of the dispersed phase in binary blends was calculated with graph transition technique, which possessed log-normal distribution characterization. The power spectrum images corresponding to small-angle light scattering images were obtained by two-dimensional fourier transformation of binary images. The correlation distances a(cf) and average chord length (l) over bar (f) have been calculated by intensity, of power spectrum images and that was the same as a(c) and (l) over bar. (c) 2006 Wiley Periodicals, Inc.