Abstract: The well-preserved dinosaur egg fossilsrecently found in Qiyunshan area, Anhui Province are the key to studying the living environment and the extinction of dinosaur fauna in the Late Cretaceous period. In order to discuss the palaeoenvironment and palaeoclimate, X-ray Diffraction (XRD), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) were used to analyze the composition of macro minerals, major elements and trace elements of the dinosaur eggshells, egg core and the surrounding rock. The results show that the main minerals of dinosaur eggshells are calcite and quartz whereas the mineral of the interior is the same as the exterior of the eggshell and is mainly quartz. Major elements include Ca, Na, Mg, K, Al, Fe, whereas trace elements include Sr, Zn, Ba, As, Ti, V, Cr, Co, Ni, Cu, Mn, Pb, La, U, Ir. The average content of Sr in the eggshells was 6199.3×10^-6, higher than most of the eggshells from Xixia of Henan province and Nanxiong of Guangdong province. The average content of Ir in the eggshells was 59.6×10^-12. Sr and Ir show an obvious abnormality compared with the background values, which may be caused by absorption of harmful elements during material exchange between dinosaur body and the outside world. The accumulation of As, Mn, and Pb and the lack of Zn may lead to the poisoning of dinosaurs and then extinction. The increased Fe content in the surrounding rock indicates that the palaeoclimate in Qiyunshan area during the Late Cretaceous was dry and hot, and the content of Ir, which has a positive correlation with Fe, increased with the increase of Fe. Moreover, the closer to the Cretaceous-Paleogene (K/T) boundary, the higher is the content of Sr and Ir in the surrounding rock, which may be one of the reasons for the extinction of the dinosaur fauna in the area. This conclusion provides a basis for the study of the living environment of the dinosaur fauna in Qiyunshan area.