Abstract: To identify the propagation paths of multiloop process oscillations in process industry and locate the origin of the oscillation disturbance, a novel method based on Granger causality test is proposed. Preprocessed by existed spectral analysis, process variables of oscillatory control loops with similar frequency components are selected for Granger causality test, which can reveal the complex causality among the selected process variables. The causality is visualized in the form of causality diagram, which represent the propagation paths of the oscillations and can be further simplified by the understanding of process knowledge. Less significant causality pathways are filtered out by manual cuttingoff threshold searching. The resulting diagram represents the main oscillation propagation paths, which is traced to identify the source of the oscillation disturbance. Both simulated and real plant data tests are presented that the proposed method is feasible.