Through molecular design,2-chloroethyl isocyanate(CIC)is bonded onto the surface of polyvinyl alcohol microspheres(CPVA)to obtain CPVA-CIC.Sodium p-hydroxybenzene sulfonate(HSS)is solidly loaded on CPVA-CIC to produce CPVA-HSS functional microspheres,which are characterized by means of infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and zeta potential.The effects of main factors on the loading capacity of the grafted microspheres are examined and investigated.The adsorption performance and mechanism of CPVA-HSS for theophylline molecules are explored.Experimental results indicate that through CIC modification,HSS anionic monomer is successfully solidified on the surface of CPVA substrate to form CPVA-HSS.The adsorption of CPVA-HSS for theophylline has reached equilibrium in 5 h.Thanks to its strong electrostatic interaction,CPVA-HSS's adsorption capacity can reach 60 mg·g-1 in an aqueous solution with a pH of 5.The adsorption capacity of CPVA-HSS increases with the decrease of temperature,and declines with the increase of medium salinity.CPVA-HSS functional microspheres exhibit good reusability.