Abstract: In this paper, we proposed a novel technique to fill the impedance matrix based on triangular patches. Every pair ofthe triangular patches has 9 common edges at most. There is some common part in integral equation between every pairs ofcommon edges if these edges locate on a pair of triangular patches. So we can elicit the common part in integral equationsbetween the different triangular patches, and distribute the values over the interaction between the relative common edges. In thiscase, if the object has a closed geometry shape, this matter to form the elements of impedance matrix can lead to save 4/9 fillingtime than the conventional way at least. Several examples show that numerical results educed from the novel technique agree verywell with that form the traditional methods.