Studying the physical and chemical characteristics of marine atmospheric particles will help us to understand the role and impact of particulate matter in the marine atmosphere. This study compares the physical and chemical characteristics of atmospheric particles collected in spring and autumn over Bohai Sea at the single particle level. Single particle analysis was conducted by computer-controlled scanning electron microscope with energy disperse X-ray analysis. The results show that the atmospheric particles in these two seasons are affected by marine source, dust storm, and anthropogenic sources in different extents. We found a significant fraction of particles contains iron during non-dust period which possibly come from the anthropogenic sources during the October cruise. The mixed state index was presented and linked to the differences in the sources, aerosol composition, and the aging processes.