The work aims to study the influence of structure and embedding method of cathodic protection coupons on its grounding resistances. The common boundary element of coupons was established based on boundary element platform. The influence and influence laws of the shape, exposed area, shell size, buried depth and soil resistivity on grounding resistances of coupons were discussed. Meanwhile, the proportion of grounding resistance in the total resistance of coupon to earth was calculated and then compared with the simulation results of boundary element. The proportion of grounding resistance in total resistance of the coupon to earth increased with more negative polarization potential, and the maximum proportion was close to 95%. The grounding resistance decreased by about 2 times with the exposed area of coupons increasing from 6.5 cm2 to 50 cm2. Under the same exposed area, the circular coupons had the largest grounding resistance and the rectangle coupons had the smallest grounding resistance, and the difference between the two was about 1.7 times. When the shell area increased to 7 times of the area of coupon, the grounding resistance approached the maximum value. The grounding resistance of coupons increased linearly with the increase of soil resistivity. For single layer soil environment, the change of grounding resistance of coupons was less than 2% with buried depth below 0.2 m. In the boundary element simulation results, the calculated grounding resistance of circular coupon with area of 6.5 cm2 and buried depth of 0.2 m was 1.4% smaller than the test result, and the simulated value of the columnar coupon with area of 6.5 cm2 was 6.3% smaller than the experimental value. The experimental results of grounding resistance are in good agreement with the boundary element simulation results, and the model is reasonable.