Charged ultrafiltration membranes have been used for several applications due to their separation ability that combine sieving mechanism and electrolyte diffusion. In this work, diffusion performance of solutes through polyvinyl alcohol/polyallylamine membrane was studied. Glutaraldehyde was added as crosslinking agent, while NaCl and CaCl₂ were used as solutes, either as a single or double solute. The results showed that for single solute diffusion, diffusion of Na⁺ and Ca²+ were only affected by swelling degree. Meanwhile, at diffusion of double solute, there was interaction between Na⁺, Ca²⁺, and membrane charge that made Na⁺ ions moved faster and Ca²⁺ ions moved slower.