In this study, we assumed that the cement paste and mortar are continuums and proposed a rheological constants estimation equation that can be applied to both cement paste and mortar. After that, the effectiveness of the proposed equations was verified using MPS analysis, and the effectiveness was confirmed in cement paste and low-fluidity mortar. However, for high-fluidity mortar, the actual measurement results could not be reproduced well by MPS analysis. In the case of high-fluidity mortar, the actual measurement results could be reproduced well in the MPS analysis considering thixotropy .