We have investigated the drying process of latex dispersion coating from the perspective of particle packing process. The behavior of particle aggregates in latex dispersions under shear flow was evaluated based on rheological measurement: particle aggregation under steady shear is related to apparent viscosities and time variation of elastic moduli shows reconstruction of aggregates. The effect of applied shear strain in coating on the thinning behavior of the latex dispersion coatings has been investigated. We found that the packing fraction of particles at the end of a constant film thinning rate period or concentration intricately changed with applied shear strain and glass transition temperature, T_g, of latex particle. If particles are completely dispersed, deformable particles having lower T_g are packed up to a maximum packing density, showing a very short falling drying rate period. In the case of insufficient shear strain application, however, aggregates formed a loosely packed layer, resulting in the emergence of a clearly decreasing thinning rate period. In contrast, hard spheres having the highest T_g formed a loosely packing particle layer similar to aggregated lower T_g particles.