The focal mechanisms of 62 moderate-small earthquakes since 1980 in the ＂Huoshan Seismic Window＂ region are calculated with the method developed recently by Snoke which combines the first motion of P, SV and SH waves with their amplitude ratios. Based on these abundant focal mechanisms, mean tectonic stress field in the ＂Huoshan Seismic Window＂ region is inverted with the method of average stress tensor. The result shows that the ＂Huoshan Seismic Window＂ region is horizontally compressed nearly in EW direction and horizontally dilated nearly in NS direction, which is in accordance with statistical results of focal mechanism parameters. We estimate the difference （also referred to as consistency parameter 0） between the force axis direction of focal mechanism solution and the mean stress tensor, then further analyze the variation characteristics of/9 versus time, and the relationship with moderately strong earthquakes in the Eastern China region. The result indicates that 0 in the ＂Huoshan Seismic Window＂ region are in good correspondence with moderately strong earthquakes in the Eastern China region. When 0 is lower than the mean value, corresponding moderately strong earthquakes may occur in the Eastern China region.[著者文摘]