The effects of pH and electrolyte concentration on the adsorption onto bleached sulfate(softwood) cellulose fibers of high-molecular-weight cationic polyacrylamides (C-PAM) (copolymers of acrylamide and N,N'-(diethyl aminoethylacrylate) quaternized with dimethyl sulfate) have been studied. The adsorption increases with increasing pH or decreasing degree of substitution of cationic groups (more than 7.8 mole percent of cationic groups). Nonionic polyacrylamide is not adsorbed onto the bleached softwood fibers. Initially, the addition of simple electrolytes (sodium chloride and calcium chloride) increases the adsorbed amount of CPAM, but the adsorption decreases at high electrolyte concentrations. A somewhat different and more complicated adsorption pattern was found when sodium sulfate was used. -- AATA