Abstract: The vibration energy transmission at corner interface of two infinite plates rigidly joined at arbitrary angles is studied by wave approach so as to investigate the effect of blocking mass used for reducing plane bending wave transmission. Two local coordinate systems were introduced and six new non-dimensional coefficients implying corresponding ratio of characteristic impedances of plates or blocking mass were presented to simplify formulations of transmission and reflection coefficients. Five samples were tested in experiment. Discussions were carried out based on the comparison between prediction and experiment in terms of insertion loss. It is concluded that blocking mass acts like a "low-pass filter", effective for vibration attenuation above certain frequency. The value of IL in "attenuation band" depends mainly on mass per unit length and band width of "attenuation band" on mass moment of inertia per unit length of the blocking mass.