Its known that traditional fiber current differential protection cannot be directly applied to transmission lines with shunt reactors without compensation.In view of polarized current travelling wave-based directional relay used in lines with shunt reactors，an in-depth analysis is made of the process of travelling wave through shunt reactors，the transmission frequency domain with shunt reactors and the impact on polarized current travelling wave-based directional relay based on wavelet transform.The results show that lines with shunt reactors will not affect the direction of the transient traveling wave head nor the extraction of the wave-frequency line.Therefore，polarized current travelling wave-based directional relay can be directly applied to transmission lines with a shunt reactor.Both EMTP simulation and actual device test results show the excellent characteristics of the protection in lines with shunt reactors.