The present invention provides a composite wall panel with good thermal insulation and sufficient strength for structural use which is designed for the fabrication of energy efficient building. The composite wall panel of the present invention comprises a foamed concrete core with sufficient compressive strength and low thermal conductivity which is sandwiched between two lightweight ductile fiber reinforced cementitious composite (FRCC) protective layers with low thermal conductivity, good barrier resistance to moisture/chloride ion/gas, multiple cracking as well as certain amount of steel reinforcements. These composite wall panels are useful in a variety of buildings in both cold and hot regions.