This paper analyzes the ground penetrating radar(GPR)method in detection of cofferdam blasting toe-shooting effect based on a real example of Jinhai phase Ⅲ east cofferdam engineering in Lianyun new city,Jiangsu province.According to the explanation and analysis of the radar image,we can obtain the specific scope and depth of the cofferdam riprap.It provides the basis for evaluation of the blasting toe-shooting effect and the reference for the subsequent construction.It shows that GPR is an effective method in the detection of blasting crowded silting effect.