Abstract: For the purpose of extending the urban geological work, our party has conducted since 1986 ground radiometric measurement over an area of 1632 km² in Dalian and, on such a basis, made information conversion for gamma radiation level, thus extending the service of radiometric measurement which was formerly only used in geological work, and raising the effectiveness of ra-diometric measurement.This paper describes in detail the natural environment gamma radiation level of Dalian area and distribution of air-absorbed doses. Two maps, namely. the division of natural eivironment ionizing radiation ra tes in Dalian area and the distribution of air-absorbed doses of natural envi ronment ionizing radiation, have bean compiled.The completion of this work has provided environmental radiogenic ba ckground data for Dalian City and made a gratifying stride in applying geo physical and geochemical prospecting to the study of urban environment.