Particle concentrations of metallic elements in ambient air were determined using a micro-orifice uniform deposition impactor (MOUDI). Comparisons were also made of particle concentrations of various sizes (PM18+, PM18–10, PM10–2.5, and PM2.5–1) sampled at Westin Park and at Gung-Ming Junior High School (Taichung airport). Comparing the particle sizes of PM18+, PM18–10, and PM10–2.5 revealed higher concentrations in Westin Park than those in Gung-Ming Junior High School (Taichung airport). The only exception was PM2.5–1, indicating higher concentrations at the Gung-Ming site. The average particle concentrations order was Gung-Ming Junior High School (Taichung airport) > Westin Park for the particle size of PM2.5–1. According to analysis results of various particle sizes of metallic elements Zn, Ni, Cu, Cd and Pb in the ambient air, the relative concentrations were PM18+ > PM18–10 > PM2.5–1 > PM10–2.5 for all sampling sites. The only exception was particle-bound mercury Hg(p), likely owing to the proximity of the Taichung airport to the Taiwan Strait (approximately 11.6 km). Moreover, Dragon Steel Plant, Han-Shian Aerospace Industrial Development Corporation and Quan-Lien Industrial Park were located nearby.