The effect of loss in the photovoltaic-photorefractive crystal on the solitary evolution of a Gaussian beam is investigated. It indicates that, for a given photovoltaic-photorefractive crystal and a proper Gaussian beam, the loss will give rise to the continuous change in amplitude and cross-section during the transmission of the incident Gaussian beam, and for long-distance transmission it will eventually lead to the divergence of the incident waves. For the strong mismatch case, the cross-section of Gaussian beam first compresses and then expands, while the amplitude at the beam center first decreases, then increases and decreases again. In the case of weak mismatch, the intensity and the cross-section will monotonically decrease. It is found that the loss in the crystal can make a mismatched incident Gaussian beam evolve to a matched one, and then become to a steady-state bright soliton.