Abstract: A new method was proposed by combining benchmarking and data envelop analysis (DEA) to evaluate the performances of public administrative departments. With the newmethod, the effective decision making units for a public administrative department are primarily determined with DEA. The primarily determined effective decision making units are combined with benchmarking units, and then the final effective decision making units are obtained by comparing more departments with DEA. The new method avoids subjective weighting in traditional evaluation of public administration units, and the disadvantage of relative effectiveness of DEA.