With the increasing popularity of wireless sensor network and GPS technologies, uncertain data as a new type of data bring new challenge for the data processing methods. Data broadcasting is an effective means for data dissemination in mobile computing environment. Definition of the mean uncertainty ratio of data is presented and a broadcasting scheme UDBS is proposed for uncertain data dissemination. Simulation results show that UDBS can reduce the uncertainty of the broadcasted uncertain data effectively at the cost of minor increase in data access time, in the cases of single broadcast channel and multiple broadcast channels.