Abstract Using Bohai Bay region GPS rate data from 1999 to 2013, Ying-Wei fault zone is divided into two blocks, and we calculate the principal strain rate and the strain rate on the fault zone. The regional strain-stress field calculation results are studied. Results show that the 1999-2011 Bohai Bay regional crust as a whole presents NEE-SWW compressive stress and NNW-SSE tensile stress effect. For 2011-2013, the regional crust presents a N-S direction, tensile stress is nearly in an E-W direction. The main cause of the change is the Japan 3.11 earthquake in 2011. Bohai Bay area is different in localized changes obviously. The Ying-Wei fault zone presents normal strain and the shear strain rates are also different at different times; in 1999-2011 it presents dextral shear strain-shear stress, whereas in 2011-2013 it shows sinistral shear strain-shear stress.