The parallel algorithm for nonlinear dynamic analysis of large structures is presented using domain decomposition and preconditioned conjugate gradient(PCG) technique. In the formulation called the global interface formulation(GIF), the PCG algorithm is applied on the assembled interface stiffness coefficient matrices of all subdomains. Newmark-β average acceleration technique is employed for time integration. Numerical results indicate that the proposed GIF formulation is superior to the conventional domain decomposition algorithm.