The obvious differences of environmental background and administration between urban and rural increasingly influence the Non-piont contamination. The study about 162 samples of street dusts from central city, satellite city, township, village and urban village showed that street dusts on impervious surface of urban and rural significantly affected heavy metal contents and particle size distributions in different urban and rural areas. The unit area mass of Pb indicated on the contrary that concentration of Pb in street dust was the higher in urban than in rural which was also in all size of the particle distribution. The concentration of Pb was higher in particles with finer grain size. The particles bigger than 150 μm fluctuated greatly. Loading on a grain size fraction of fine particles in urban road was higher than rural road. The fine had a phenomenon of “premium”, while the coarse was “discount”. The research findings imply that urban and rural areas should take different appropriate methods to control no-point pollution. Otherwise, particle size distribution is a key factor affecting heavy metal contamination in street dusts, which should be paid more attentions.