Abstract: The 3D printing filaments based on ABS/thermoplastic polyurethane (TPU) blends were prepared by a melt blending method. These 3D printing filaments were subsequently processed to the standard test samples by fused deposition modeling (FDM), and their modeling performance, mechanical properties, microstructure and rheological properties were investigated. The results indicted that the introduction of TPU improved the modeling performance of ABS. With the addition of 20 wt % of TPU into ABS, the warp shrinkage disappeared in the modeling process. At this weight fraction, the molded sample obtained the enhanced notched impact strength of 18.81 kJ/m2 and the declined tensile strength of 32.92 MPa, which increased by 95.94 % and decreased by 8.5 %, respectively, compared to those of pure ABS. Morphological observation indicated that the molded sample presented ductile fracture at a weight fraction of TPU over 20 wt %. Moreover, the roughness of the impact fracture surface with an increase of TPU content and some holes were observed. The rheological investigation indicated that there was good compatibility between ABS and TPU, and the increase of TPU content enhanced the diffusion capability of macromolecular chains for these two polymers.