The paper deals with the sorts of site ground earth classification, the fuzzy feature embodied in definitions of both near earthquake and remote earthquake, site earths characteristic period and the evaluation formulas comprehensionally in calculation of the relative dynamic characteristic parameters.

4 magnitude,and Bohai Strait near earthquakes of 4.

Relationship between the geomagnetic transfer function and the local earthquakes in Ningxia area;

Discussion about determining local earthquake magnitude with displacement and velocity obtained from digital records;

Damage mechanism of frame structures under action of near-field earthquake;