In order to analysis the cable structures with pulleysliding on the cable, or cable sliding under pulley, a new element wasdeveloped. The three node element, which is called cable-pulley, models onesegment of cable supporting pulley, and takes the center of pulley as themiddle node, the two ends of the cable segment as the other two nodes. Thederivation was based on the foundational principles of finite elementanalysis, and the relation of the forces in the element at equilibrium statewas used. This new element simplifies computations by automaticallyadjusting the cable on each side of pulley in order to maintainequilibrium. Examples proved the correctness of the derivation and theprogram developed by the author, and presented its practical usage. Theexplicit formulas of matrixes composing the stiffness are given. The elementcan be incorporated into conventional finite element analysis schemes, toanalysis the cable structures in service or during construction.