In order to obtain the influence of chip position and fix methods to dynamic property of Plastic Ball Grid Array (PBGA) under vibration environment. In this paper, a group of specified PBGA assembly chips which contain different structure and material parameters are designed and produced. ANSYS is used to build up the finite element model. In modeling process, simplified PBGA structure accompanied with numbers of solder joints are utilized to decrease the calculation. From simulation, 1st frequency and deformation can be achieved under different fixed ways. Experimental modal analysis method is combined with the dynamic test under different consolidations. Finally, take Side Four-points fixed way as an example to compare the correspondence and difference between the simulation and test. Results show the ways like make the chips on four-point board; increase the constraints; make chips near the constrains can well improve the dynamic property.