Four flat and elongated (F&E) contents (0%, original, 30%, and 40%) were investigated to evaluate the effects of F&E particles on the performance of porous asphalt mixture ( PA). Laboratory tests including volumetric determination, two-dimensional image analysis, Cantabro loss tests, breakdown tests, and permeability tests were conducted to evaluate the volumetric properties, the state of stone-on-stone contact, durability, skeleton stability and permeability of PA, respectively. The test results indicate that the F&E content was a significant factor for total air voids, aggregate skeleton break down, and permeability. The functionality, rutting resistance, long-term durability, and skeleton stability decrease with the increase of F&E content since F&E aggregates in porous asphalt mixtures have a tendency to breakdown. Compared with traditional dense graded mixtures, PA is more sensitive to the F&E content due to an open graded aggregate structure. Therefore, the stricter requirement for F&E content should be met for porous asphalt mixtures than the one for traditional dense graded mixture.