By means of high resolution field emission scanning electron microcopy (FESEM) and image analysis (IA), microscopic morphologies and the number-size and volume-size distributions of different types of individual inhalable particles collected in Macao in summer of 2007 were investigated. The results showed that the soot aggregates and mineral particles were ubiquitous in the PM10 of Macao in July, 2007. The mineral particles mostly showed an irregular morphology and the soot aggregates displayed chain-like and fluffy morphology. The soot aggregates accounted for approximately 30%-40% in average by number, and the mineral particles accounted for approximately 20%. The relatively higher percentages of more soot aggregates implied that emission from motor vehicle exhausts was serious in Macao during summer. The number-size distributions revealed that the majority of the particles in PM10 of Macao were fine particles, with the equivalent diameter being concentrated in a range from 0.2-0.4 microm. A distinct spatial difference existed in the types of particles collected at different sampling sites. Soot particles dominated the busy transportation sites and the tunnel site, while the mineral particles had a higher proportion at the dock site.