This study presents the testing of 7 hwangtoh-based cementless concrete mixes to explore the significance and limitations of the development of environmental friendly concrete without carbon dioxide emissions while maintaining various beneficial effects. Hwangtoh, which is a kind of kaolin, was incorporated with inorganic materials, such as calcium hydroxide, to produce a cementless binder. Mechanical properties of hardened concrete were measured: including compressive strength gain, splitting tensile strength, moduli of rupture and elasticity, and stress-strain relationship. In addition, the recorded mechanical properties were compared with those of ordinary portland cement (OPC) concrete and predictions obtained from the design equations specified in ACI 318-05 and CEB-FIP for OPC concrete, wherever possible. Test results showed that the developed hwangtoh-based concrete have highly effective performance and great potential as an environmental-friendly building material.