A system for investigating rheological properties of grease, the system including grease sample preparation arrangement for preparing a grease sample with a predetermined quantity of grease, at least two sample holder plates for holding the grease sample by sandwiching the grease sample between the sample holder plates, wherein at least one of the sample holder plates is transparent, and a loading system for generating a predetermined force acting on the grease sample sandwiched between the sample holder plates by pressing on the sample holder plates such that a spot formed by the grease sample on the sample holder plates is expanded. The loading system can include at least one transparent portion enabling a continuous observation of the expansion of the spot while the predetermined force is acting on the grease sample.