Abstract: The interactive probabilities between medium and medium, medium and particle as well as particle and particle were obtained using computer simulation calculation based on three dimensional lattice models. The relational expression of viscosity η and effective volume fraction φ_{eff of the latex systems was resulted from the above calculating results. The concordance in form and difference in content of both Batchelor formula and Simha formula were elaborated by using the relational expression, further more, the effects of interaction between medium and particle as well as interaction between particle and particle on viscosity of poly(methyl methacrylate) latex systems were discussed by using rheological data.}

Key words: latex particle, interaction, viscosity