Conceptual cost estimation during the early stage of a construction project plays important role for feasibility analysis and project planning. Traditional approaches rely heavily on experienced engineers, and may cause loss of conceptual estimation knowledge of the firm. This paper proposes a method integrates a previous developed conceptual cost estimation method (PIREM) with the ANFIS neuro-fuzzy system for mining of cost estimation data. A case study of residential building projects in Mainland China is conducted to test the proposed method. The testing results show that the proposed method does not only achieve high system accuracy, but also provide many features desirable for estimators such as explicit fuzzy decision rules and graphical sensitivity analysis presentation.