A M_S4.2 earthquake occurred on August 14,2015 in Changli,Hebei. Its location was close to that of the 1976 Tangshan earthquake,and it's the largest earthquake in 2015 in the Capital Region. This paper calculated the moment tensor solution of this earthquake and apparent stresses of small earthquakes in 2015 in the nearby region. We discussed regional crust stress by using these calculations. Most previous researches study the azimuth of principal axis. Here we showed information of absolute stress value of earth crust by using earthquake apparent stress. We calculated seismic moment using 2 methods:① inversion of moment tensor by fitting theory seismograms and observed ones,② integration of broad band average seismic spectrum. The seismic moment calculated from these 2 methods are similar,and demonstrates the validation of these 2 methods. We conclude that:① the stress field of earth crust in study area is coincidence to that in the Northern China,but it also shows regional characteristics,② the distribution of earthquake apparent stress is similar to those in the past 10 years which implies that the future seismicity remains unchanged.