NOVELTY - A wavelength conversion resin composition contains a fluorescent material, resin particles and dispersion medium resin. The resin composition has value (A1( lambda )) of 3x 10-4 (O.D./ mu m) or less in maximum-absorption-wavelength ( lambda max) (nm), derived from intensity of transmitted light which is obtained when incident light having light intensity of I0( lambda ) is incident to a resin film produced from resin composition and having a thickness of t ( mu m), and intensity of transmitted light which is obtained when the light is incident to a reference resin film.    USE - Wavelength conversion resin composition for transparent layer of solar cell module (claimed).    ADVANTAGE - The wavelength conversion resin composition provides solar cell with improved electric power generation property. The wavelength conversion is stably and efficiently enabled using the resin composition without deterioration.    DETAILED DESCRIPTION - A wavelength conversion resin composition contains a fluorescent material whose maximum absorption wavelength in light-absorbency spectrum is lambda max (nm), resin particles and dispersion medium resin. The resin composition has value (A1( lambda )) of 3x 10-4 (O.D./ mu m) or less in maximum-absorption-wavelength ( lambda max) (nm). The value (A1( lambda )) is derived from relation: A1(( lambda ))=(log(I0( lambda )/I( lambda )))/t-(log(I0( lambda )/Iref( lambda )))/tref, where I( lambda ) is intensity of transmitted light which is obtained when incident light having a light intensity of I0( lambda ) is incident to a resin film produced from the resin composition and having a thickness of t ( mu m), and Iref( lambda ) is intensity of transmitted light which is obtained when the light is incident to a reference resin film produced from a reference resin composition having the same composition as that of the resin composition excluding fluorescent substance and resin particles and having thickness of tref ( mu m). An INDEPENDENT CLAIM is included for evaluation of wavelength conversion property of resin composition, which involves evaluating wavelength conversion efficiency based on value (A1( lambda )).