The application of ground-probing radar to the engineering-geological inve-stigation has just begun in China. This paper describes the testing results of theintroduced pulso-EKKO IV pulse time-domain ground-probing radar produced by the Canadian Probe and Software Company on engineering sites. Geologists from the China University of Geosciences (Wuhan) successively made experi ments and investigations on eight engineering sites in less than one year, which involved 14 geological problems concerning five different types of rocks and soils. As a result, large quantities of data and part of stuff on drilling and dig ging verification have been obtained. These results demonstrate that this instru mental system has fairly good capacity of geological recognition, can solve to leseer or greater extent many engineering-geological problems that have been posed, possesses sufficient ability to reach the required engineering-geological depth and shows fairly high resolution power. The instrument is portable and highly automatized and the efficiency of on-the-spot work is very high. Besi des, the interference of urban environments is small, the work is nondestructive, and working sites can be chosen at will.