The increased vulnerability of many urban areas is a major reason of concern. Debris flow hazard control and mitigation in the urban areas have become one of key aspects for disaster reduction at home and abroad today. Over the past years, the debris flow warning acquired great attention for the hazard mitigation. Therefore emphasis should be given to the loss reduction in urban areas, which requires the up-to-data warning methods in order to make recommendations for prevention, preparedness and response once the hazard occurred. This paper has indicated that improvements of the current situation of debris flow hazard warning would help to reduce losses in urban areas significantly if an extreme scale of debris flow was to recur abruptly. Based on analysis of past performance of debris flow warning and existing problems, it is worth to pay further attention to develop study on debris flow monitoring and warning associated with the urban areas. In order to solve the difficulties of monitoring and warning at present, the formative mechanics of debris flows, application of the new technology and methodology as well as hazard mitigation decision support systems should be combined with warning system. Emphasis will be confined to integrated study on urban digital hazard mitigation system, urban hazard prevention scheme, risk and evacuation management, and loss evaluation.