[en] This paper presents electron paramagnetic behaviors of BiSrCaCu₂O_y high-T_c superconductor at different temperatures by observation of electron paramagnetic resonance (EPR). No EPR was detected below superconducting transition temperature T_c besides a signal near zero field. However, two types of EPR signals exist in this sample above T_c. One of them (at the higher field) is almost independent of temperature and its behavior is similar to that of the free electron. Another one (at the lower field) may be related to copper and oxygen ions and its average Lande Factor bar g-value, EPR linewidth and integrated intensity seem to change anomalously at around 240 K. The authors propose that the anomaly observed may be due to that the sample undergoes a displacive phase transition at around 240 K