Abstract: Water gushing is common disaster in tunnel construction,and may be induced by many causes.Taking the water gushing of section NK12+088 of Xiamen submarine tunnel as an example,based on the theoretical calculation and laboratory tests and combined with geological engineering conditions of the section,the causes of water gushing were analyzed from three aspects: penetrating breakage of ground water,integration in water and emergence characteristics of surrounding rock in tunnel face.It was shown by the analysis that in completely weathered and strongly weathered surrounding rock penetrating breakage might happen due to piping,and the disintegration would be basically accomplished in seventeen minutes.Water gushing appeared in the location of rock vein.The concentration of dispersive penetration point was the dangerous mark of water gushing.