Research methods: Taking the underground river found in the Wulong tunnel for example，this paper carries out the statistics，analysis and summary by applying the karst developing theory with integrally-surveying method.
Research results: The developing flow area of underground river is divided into smooth area and clogging area which solves dispute on karst developing rules and how to deal with of WuLong tunnel for long time and can be used widely for survey and engineering treatment of underground river in the tunnel under the similar conditions.
Research conclusions: Based on the situations of transverse slope，length and filling materials of the underground river revealed by excavation in course of construction，where is the underground river located，in smooth area or in clogging area could be judged，through which the engineering treatment and possible direction of relocation of line could be guided macroscopically ， and correspondingly the geological forecast could be conducted according to the location of the underground river ， for the purpose of avoiding the appearance of disaster.
2007, Vol. 24 
