Abstract: The paper improved the C4.5 algorithm, and then used C4.5 algorithm and an improved C4.5 algorithm through comparative analysis on the quantities bill valuation of municipal road engineering case, extracted classification rules of general applicability at random verification of classification rules. It can be found that the classification rules have universal applicability, which can help the project cost related practitioners to quickly predict and improve the efficiency of decision analysis.

Key words: C4.5 algorithm, municipal engineering, engineering cost