Modeling the formation of haze by methane photolysis products requires knowledge of the methane altitude profile and optical data at two wavelengths to determine the two free parameters: the cross-section-weighted mean radius rc and the particle material density &rgr;. Using Voyager ultraviolet spectrometer measurements of CH4 and haze combined with the haze brightness profile determined by the narrow angle camera, we infer a haze optical thickness of 0.024 at 1500 ¿ and 7.8¿10-3 in the spectral range of the narrow angle camera centered at 4700 ¿, &rgr;/&ggr;=0.36¿0.1 g cm-3 (&ggr; is the quantum yield of condensate), and values of rc varying from 0.1¿0.02 μm at 30 km to 0.15¿0.03 μm near the surface. Other auxiliary properties of the haze are also determined. The value found for &rgr;/&ggr; corresponds to a packing coefficient of 0.6&ggr; if C2H4 is the main condensible species. ¿ American Geophysical Union 1992