Abstract: ; The writer tries to bring creatively up a new way to research the ecosystem environment with natural gamma ray spectrum data. The data of natural gamma ray spectrum logging are of well conformity with the contents of thorium, uranium and potassium obtained by surface gamma ray survey, laboratory analysis and aerial gamma ray spectrum survey. The radioactivity variation of the shallow part of Yellow River delta with the natural gamma ray spectrum logging from 16 wells is studied. The results show that the contents of thorium, uranium and potassium in shallow parts increase with the enhanced degrees of oil exploration and developments, and their contents in the Yellow River delta are lower than the mean richness in the crust.