Abstract: At present the most promising nondestructive testing, geophysical survey techniques-Ground Penetrating Radar (GPR) system has been concerned and been researched widely. This paper carried on the theoretical analysis on it, and combined with the characteristics of wood, applying the ground penetrating radar in the nondestructive testing technology to wood non-destructive testing ( NDT ). At the same time, this paper briefly introduced the foreign existing tree radar unit (TRU) system, and aimed to apply the basic principle of GPR to make an analysis about theoretical feasibility that GPR applied to wood NDT. Because of complex components the wood itself holds, the dielectric properties are influenced by many factors, and then there still exist great difficulties in analyzing the collected electromagnetic wave objectively. But this article enumerates the GPR processing, analysis and interpretation methods, and it is to point out that if the plot of tree radar is analyzed reasonably and selectively, the inner decay and empty features description by GRP can be more scientific and accurate.