Ca²⁺-ATPase from rabbit skeletal muscle sarcoplasmic reticulum vesicles was solubilized by nonionic detergent C₁₂E₈ and purified in a reactive red-120 agrose affinity column.Determined by 7.5% SDS-PAGE,the purity of Ca²⁺-ATPase was increased from 65% to 99% and the purified Ca²⁺-ATPase exhibited higher ATP hydrolysis activity.