Based upon a beam propagation method, a model of 1.084 μm Nd:Ti:LiNbO3 waveguide laser end-pumped by a laser diode has been proposed in this paper. The laser gain and pump absorption were described through the complex atomic susceptibility of Nd3+ ions. By using a diode laser as the pump source, the interference effect between the forward and the backward light waves was considered and the population inversion spatial effect was given. Moreover, the values of absorption and emission cross section were modified. A good correspondence can be got between the theoretical and experimental values.