Abstract: Oscillatory wheel load fluctuation of considerable amplitude is always observed in railway trains traveling at high speed. The study describes a new continuous method for measuring lateral force between wheel and rail without special wheelsets equipped with strain gauges and slip rings or telemeters. Track strain response upon wheel/rail interaction is measured based on PVDF (polyvinylidenefluoride) strain sensors and processed to generate a condition index which directly reflects the train operation condition. This approach is verified by finite element simulation and experimental test and the preliminary results show that this electromagnetic immune system provides an effective alternative for lateral wheel/rail interaction force measurement. The method significantly increases the efficiency of maintenance management and enhances the stability for train operation and more importantly, avoids derailment timely.