There is large number of joint in a machine tool structure. The performance of the whole machine tool structure is affected by these joints. In order to predict and evaluate the performance of machine tool structure,it is required to approach an experimental method to obtain the foundation characteristic parameters of joints. A new method to identify the damping parameters of joints is proposed based on the acceleration transfer function. The calculation of the stiffness matrix and mass matrix can be avoided by computing the real and imaginary parts of the acceleration transfer function. It is a simple and useful method to identify the damping of a joint. The method is verified through the foundation parameters experimental of joints.