This paper deals with a numerical model for the time-dependent analysis of steel and concrete composite beams with partial shear connection. A linear partial interaction theory is adopted in formulation of slip behavior, and a linear load-slip relation is assumed for computational convenience. On the basis of governing equations representing the slip between steel beam and concrete slab, the numerical model is derived through the force equilibrium equations and strain compatibility conditions at each node, with an assumption of piecewise linear distribution of the bending moment. In advance, the migration of the stresses from the concrete slab to the steel beam and the increment of deflections, which occur gradually with time as a result of creep and shrinkage of the concrete part, are investigated by a numerical model proposed in this paper. The proposed model results in an effective use in simulating the slip and time-dependent behavior of multispan continuous composite beams regardless of applied loading type. Finally, the correlation studies between analytical and numerical results and several parameter studies are conducted with the objective to establish the validity of the proposed model.