Abstract: In order to improve the utilization of integrated grounding wire (IGW), the inflences of its radius, buried depth, interval of transversal connections and soil resistivity on grounding effect were analyzed by taking IGW grounding impedance and shunting coefficient for rail current as the assessment indices of the grounding effect. The research result shows that the grounding impedance and the shunting coefficient are sensitive to the changes of IGW radius, interval of transversal connections and soil resistivity, but insensitive to buried depth. A comparison between the theoretical results and the test ones on Suining-Chongqing ballastless railway indicates that differences in the grounding impedance and the shunting coefficient are respectively 17.3% and 11.4%.