Abstract: An efficient adaptive beam tracing method is proposed. The proposed method based on ray tracing models the electromagnetic wave front by means of beams to mitigate the spatial sampling artifacts. In this method, the beam can be adaptively spitted during traversing the environment; also the reception sphere is eliminated to avoid the double counting problem of traditional ray tracing. An efficient beam-triangle intersection algorithm based on Pluecker coordinates is also discussed. With this efficient intersection algorithm, the proposed beam tracing method enjoys high computation efficiency. The proposed method is applied to channel perdition in complex indoor environment and its accuracy and efficiency is valid by comparing the result in public literature.