Investigation and evaluation of the natural radiation level of Qingdao City were conducted by Qingdao Institute of Marine Geology from 2003 to 2005. The radioactive level of Qingdao City remains within the safe range of the natural background level, although the average dosage rate of the terrestrial γ-radiation is slightly higher than that of the National and Shandong Province Standard. The level of the terrestrial γ-radiation seems on the whole controlled by the local rocks. The terrestrial γ-radiation results from ²³²Th, ²³⁵U and ⁴⁰K, while ⁴⁰K or/and ²³²Th contribute more to the terrestrial γ-radiation than ²³⁸U, which is different from things of the other areas. In addition, the amounts of radionuclide contained in such materials as masonry, cement and concrete used for many construction projects like roads and architecture affect the level of terrestrial γ-radiation of the construction projects.