This paper describes methods for measurement of vibration intensity. The object is to make differences clear in effectuality of the methods to the search of exciting and absorbing points on homogeneous beams or flat plates. The intensity measurements studied are the finite difference method, the finite difference method neglecting the cross terms of the two directions in the plane and the cross-spectrum method, in which the second and third methods are compared with the first basic method. The vibration intensity maps evaluated by these methods based on computational frequency response simulations show that (1) the cross-spectrum method which holds on the assumption of complete free field is effectual for the survey of paths of vibration energy flow in the rough, but it is not effectual for the search of the exciting and absorbing points, but (2) the finite difference method neglecting the cross terms is effectual for the survey the of paths and the search of the points.