Polystyrene (PS) microspheres coated with beta-cyclodextrin (beta-CD) were fabricated via ?-ray-induced emulsion polymerization in a ternary system of styrene/beta-CD/water (St/beta-CD/water). The solid inclusion complex of St and beta-CD particles formed at the St dropletswater interface can stabilize the emulsion as the surfactant. TEM and XPS results showed that beta-CD remains on the surface of PS particles. The average size of the PS particles increases from 186 to 294 nm as the weight ratio of beta-CD to St rises from 5% to 12.5%. The water contact angle (CA) of PS latex film is lower than 90 degrees, and reduces with the beta-CD content even to 36 degrees. Thus, this work provides a new and one-pot strategy to surface hydrophilic modification on hydrophobic polymer particles with cyclodextrins through radiation emulsion polymerization.