The study was carried out in a representative coastal mudflat area in north Jiangsu Province, China. Classical statistical and geostatistical methods were employed to summarize the concentrations of the four types of element (Pb, Cr, Cd, As) in surface soil in 2009 and 2014, to analyze the effect of land use types on heavy metal content, and to determine spatial patterns and spatio-temporal variability of soil heavy metals in these two periods. Results indicated that the content was general below the widely accepted environmental quality standard (first class) for the four types of soil elements. During the five years from 2009 to 2014, soil Cd accumulated significantly across the study area, soil Pb content in the residential area also increased remarkably, and significant accumulation of soil Pb and Cd was also observed in the industrial area, whereas the change of soil Cr and As contents was not significant in each type of land use. Under the control of large-scale tide deposits and small-range human activities, soil Pb and Cr contents exhibited similar spatial patterns during these two periods, whereas the spatial patterns of soil Cd and As ahowed great difference in the two periods. The enrichment of soil heavy metals across the different land use in the study area exhibited spatial variability and directional trends. Atmospheric deposition was another important factor that influenced the spatio-temporal variability of soil heavy metals. The coastal mudflat area presently faces the problem of soil heavy metal enrichment. It ought to take preventive countermeasures, such as strengthening in situ monitoring and source reduction, optimizing industrial layout, and prompting process blocking and biological remediation to prevent and minimize heavy metal hazards.