Heavy metals have drawn increasingly more attention for its possible damage to human health and ecological environment. In order to prove up the accumulation characteristics of heavy metals in the agricultural lands on the periphery of Ningbo city in eastern Zhejiang Province and the potential ecological hazard risk, topsoil samples in the survey region were systematically collected so as to determine the content of heavy metal elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) and reference elements (Li, Eu, Sc, Sm). Through the analysis of elemental correlation, appropriate standard factors were screened out, and then, according to the standardized method, the environmental geochemical baselines of the heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in the survey region were established, so the baselines were obtained, respectively, 6.93, 0.23, 77.22, 49.14, 0.80, 30.24, 58.40 and 125.80 mg·kg^-1. Taking the environmental geochemical baselines as standard factors, the enrichment factor method was used to identify the geological background sources of heavy metals in the soils and the superposition of man-made pollution. As a result, the risk evaluation and space early warning research of potential ecological and environmental hazards of heavy metals in the agricultural lands of the survey region were carried out. The research results showed, heavy metal enrichment in the topsoils of the survey region was mainly influenced by the activities of industrial enterprises and the concentration center was densely distributed in the surrounding areas of printing and dyeing companies, which had the tendency of migration to the low-lying plains along water networks; Cd and Hg had potentially high ecological risk in the survey region; GIS system was used to achieve the spatial overlay of the enrichment factors in each sampling points, potential ecological hazard evaluation results as well as agricultural land use status map of the survey region, which realized the discrimination of the superposition of man-made heavy metal pollution and the space early warning of potential ecological hazard risk from the perspective of geographical space.