Blood lead is a reflection of environment lead in vivo, its concentration could be used to assess lead exposure of environment quantitatively, and its isotopic ratio could be used to fingerprint environment source qualitatively. In the present study, concentrations and isotopic ratios of blood lead (BPb) of four cities in China were measured by ICP-MS for the first time. The regional effects of BPb in four Chinese cities were observed in our study .The BPb levels of industrial cities (Taiyuan and Chengdu) are higher than that of non-industrial cities (Suzhou and Beijing), indicating that industrial pollution remains primary lead contamination factor. The BPb isotopic ratios are diverse with the different character of environment the individuals live in. Food-borne lead probably has replaced the air-borne lead to be the major source of BPb in Beijing. Besides, regional effect of BPb in some developed cities is partly weakened by diversity of vast majority of imported resources.