Pretreatment process is very important for ink jet printing system. Pretreatment solutions that is transferred to the cotton fabric before reactive ink-jet printing affects printing quality. In this study, the influence of the rheological properties of pretreatment thickeners on printing quality and color yield has been researched. The reological properties of the pretreatment sollution is determined mainly by the rheological properties of the thickener that is used. The influence of the rheological properties of the pretreatment sollutions which is prepared with different kind of thickeners at different concentrations, on paste add-on, penetration and colour yield values is investigated. As a result, it was observed in this study that at applied conditions the rheological properties of the pretreatment pastes applied have not a significant influence on color yield and ink-jet printing quality.