Abstract: This paper proposes the use of natural gamma spectroscopy tool for studying the ecological environment. Natural gamma spectroscopy logging has been run for shallow formations in four wells near the Yellow River delta area. The thorium content for the shallow formation in well Laohuanghekou is higher than that for other wells. The uranium content in sea water is higher than that in shallow formations on land. Radioactivity is higher in mature area than in new frontier area. All these indicate that petroleum development have certain effect on local ecological environment