The calculation formula of phase dimension and related distribution were deduced based on Mie scattering theory and employed for polypropylene/polystyrene blends,as an example. The calculation results show that, the development of phase morphology madly occurs within the first 3 min and later approaches a dynamic equilibrium under the shearing tress and interfacial tension. Further, this result indicates that the calculation formula is effective to describe the phase dimension. Meanwhile, regarding the deve...