In this research, the compacting process and rheological properties of kaolin and bio-original additive (sawdust) mixtures were investigated based on compaction pressures and times. Relative compaction curves as a function of forming pressure and time were determined, the authors enabled to precisely specify the changes of the rheological models and rheological characteristics of these powder mixtures which have variable particle compactions and size distributions. varying the compression pressure and changing the composition ratio of the kaolin and sawdust powder mixtures leads to considerable changes in the rheological properties of the prepared mixture.