In order to investigate its electronic structure and the π–d interaction, we studied magnetoresistance (MR) of β″-(EDO-TTFVO)2FeCl4. In the course of experiment Shubnikov–de Haas (SdH) effect was found, which shows that this material is a 2D metal. Below 3.5K (close to TN), MR shows a dip anomaly near 8T. The anomaly becomes more prominent and shifts slightly to higher field with lowering temperature. The dip anomaly may be caused by the transition from the antiferromagnetic to the paramagnetic states. In addition, SdH oscillations are clearly seen at 0.5K, whose cross-sectional area corresponds to 13% of the first Brillouin zone. The mass of the π-electrons is m*≃3.3me, which seems heavy as compared with non-magnetic organic conductors with similar cross-sectional areas, suggesting the enhancement of the mass due to magnetic interaction with the Fe 3d spins.