We have investigated the sum-frequency generation (SFG) of the 1.06μm beam with its harmonic beam or dye laser beam in disodium gulfosalicylate (DSS) crystal. The collinear phase-matching types, wavelengths and propagation direction of SFG in DSS crystal have been calculated and measured. The measured results are inagreement with the calculate ones, the characteristics of tunable SFG output have also heen investigated.