With Zhenezhou area as an example, this paper discusses the application of geochemical exploration to the study of environmental background values and environmental evaluation. Three heavy metal elements closely related to human health, i.e.Hg, Se and Pb, were selected for the study. A discussion is given on regional background, environmental pollution, pollution sources and pollution degrees of these three elements, with an indication of the state of their pollution in Zhengzhou area and some problems that are worth noticing.