Abstract: Theoritically, it is demonstrated that current EOFs expansion results are not true to some extent over heterogeneous network. Under identical conditions, the obvious differences between homogeneous and heterogeneous network are researched for current EOFs expansion. A revised scheme using area weighting is developed, which can to a certain degree compensate for the lack fidelity of the EOFs expansion due to heterogeneous network. According to this technique, the fiedlity of objective information from described meteorological fields is enhanced by using current EOFs method. In a practical case, the regional differences of recent warming effect are more objectively revealed by using the revised EOFs technique to surface temperature field records(network from 160 stations) in response to the trends and features of China region.