This study was conducted to compare the flexural properties and biocompatibility of experimental 3D printing resins with commercial 3D-printing resins and conventional denture base resin. Auto polymerized pour-type denture base resin (RESS LT; Retec, Germany) was used as a control group. A commercial 3D printing denture base resin, NextDent (Base, Vertex Dental, Soesterberg, Netherlands) and two 3D printing resins, White prototyping resin (PR57-W, Autodesk, USA) and Clear prototyping resin (PR48, Autodes, usa) were compared. Experimental 3D printing resins (E1, E2, E3) were made with different ratios of dimethacrylates. DLP 3D printer (VIDA, Envisiontec) was used for 3D printing. The specimens (64×10×3.3 mm) were made based on the protocol of ISO 20795-1. The flexural strength and flexural modulus were measured by a universal testing machine (Z020, Zwick, Germany) at a crosshead speed of 5 mm/min. MTT test was performed to evaluate the cell viability. The flexural strength and flexural modulus of E2 were significantly higher than those of other groups (p<0.05). Biocompatibility of all experimental 3D printing resins were not significantly different from negative group (p>0.05). E2 is considered to be a promising material as a denture base resin for 3D printing.