A serial of micro-scale cationic particles was synthesized by inverse suspension polymerization. These particles formed flocs with hydrolyzed polyacrylamide through electrostatic attraction. The structure of these flocs evolved from a bulk state to insulated microspheres at a critical salt concentration, which increased with increasingly cationic degree of particles, corresponding to the change of Zeta potential. Moreover, the adsorbance of HPAM on the cationic particles attained a maximum about 409 mg/g at 500mg/L HPAM in salt-free water and 237 mg/g at 800mg/L HPAM in 2wt% NaCl solution at 20°C according to a semi-quantitative method implemented by viscosity contrast experiment. This adsorbance difference accounts for that the electrostatic shielding effect of salt stimulates the desorption rate of HPAM.