When using for long distance transmission lines， the current differential protection suffers from influence of the distributed capacitive current. Based on distributed parameter line model， equivalence of the distributed capacitive current and the directional current traveling-wave transmission delay is analyzed and implementation mode of the traditional traveling-wave differential current protection is discussed. Furthermore， an applied protection scheme based on traveling-wave differential principle is proposed. The new scheme forms a differential criterion with the measured and the calculated current values of the same side of the line. When calculating the current， it needs not to use interpolation or voltage of the opposite side， which results in less computation and lower demand of sampling and communication rate. Simulation with ATP shows that the new scheme can eliminate the impact of distributed capacitive current effectively.