A comparative analysis of trace elements in tomato seeds from the earlier Western Han dynasty (200 B.C.) tomb in suburban Chengdu, and present tomato seeds in Chengdu Qingdao and Beijing has been performed. The intended purpose of this analysis is to provide some useful information for archaeologists and biologists to solve controversial problems involved in the place of origin of the ancient tomato seeds. To study the ancient agricultural technique, seed reservation and environment science, the trace elements in carbonized food, and the wood of a coffin have also been analyzed. The experimental results demonstrate that there are differences between the elemental composition and relative contents of ancient tomato seeds. The analysis of trace elements in historic relics from the group tombs of the minority nationality in Aba Tibetan Autonomy State of Sichuan Province is also reported. There was a significant amount of bromine and lead in the glazed pearls which is significant for the study of glass manufacturing techniques in ancient China. All experiments were done in vacuum by nondestructive PIXE analysis using a 2.5 MeV Van de Graaff accelerator, and a Si(Li) spectrometer at the Institute of Nuclear Science and Technology of Sichuan University. -- AATA