Abstract The deposition of polystyrene latex particles on polyamide fiber (Nylon 6) and polyacrylonitrile fiber (Vonnel) was studied by observing the deposited latex particles with a scanning electron microscope as a function of deposition time and pH. The latex particles on Nylon fiber at low pH were connected to each other, e.g., like a rosary, with increasing deposition time. The deposition of the latex particles onto Vonnel fiber seemed to proceed along the many grooves, which were present on the fiber surface, and it was scarcely influenced by pH. On the Nylon fiber, the deposition states as a function of time and pH were conveniently interpreted by the interaction energy estimated from the Hogg, Healy, and Fuerstenau theory using a sphere-plate model and the consideration of the heterogeneous distribution of surface groups of the fiber. On the Vonnel fiber, the interaction energy of electrical double layers calculated by regarding the fiber surface as a plate possessing cylindrical holes correctly accounted for the deposition phenomena.