With advanced 3D bioprinting technologies, fabrication of complex tissues or even organs becomes possible. One of the challenges for successful 3D bioprinting is the selection of a suitable scaffold material with a good printability. Hydrogels have attracted great attention as biomaterials for printing three dimensional scaffolds for tissues or organs. However the relations between rheological properties of hydrogels and 3D printability have not been extensively studied. In this study, alginate-based hydrogels were prepared and used as a printing material for 3D printing of scaffolds using an extrusion-based printer. Rheological studies were performed for the hydrogels with different formulas. We deduced the shear rate range for the hydrogels that bore during the 3D printing process. Furthermore, thixotropic properties of the hydrogels were investigated by applying and removing a shear rate. The measureable parameters for quantifying the quality of printing have been defined. The results will be shown and discussed. This presentation will provide some new understanding of the relation between rheological properties of hydrogels and 3D printability.