Based on near-source conditions, the authors used waveform data with magnitude larger than ML2.0 occurred in the capital circle of China and surrounding area by the Brune model. Some relevant formulas were used for calculation of a few focal dynamic parameters. The scaling relations of these dynamic parameters and characters of the temporal-spatial variations before the Wen’an MS5.1 earthquake in Hebei Province of July 20, 2006 were analyzed. The results show that apparent stress, stress drop, seismic energy and rupture radius ratio appeared relatively high in some focus areas before the Wen’an MS5.1 earthquake. These areas were mainly distributed in the North China Plain. oft-com:office:office" />