Abstract: In this paper,the method analyzing crustal deformation using empirical orthogonal function resolution is described.The observed data in Hexi area in Gansu Province is processed.The results show that the first prototype filed is helpful to judge the strong earthquake location. The weighted coefficients can indicate relative intensity of regional crustal related movement.It is one of the time criterions of earthquake risk assessment.

Key words: Empirical orthogonal function resolution, Prototype field, Vertical deformation, Gansu Hexi area