NOVELTY - An easily-bonding layer composition comprises crosslinked resin, polyisocyanate compound crosslinked with main ingredient, aggregation inhibiting agent, white pigment, silane coupling agent, and organometallic coordination compound. The aggregation inhibiting agent comprises colloidal silica. The content ratio of crosslinked main ingredient resin, polyisocyanate compound and white pigment is 0.1-25 %mass with respect to total content of composition.    USE - Easily-bonding layer composition is used for manufacture of white back surface protection sheet and solar cell module (all claimed) for electric power generation.    ADVANTAGE - The easily-bonding layer composition provides white back surface protection sheet having excellent blocking resistance and adhesiveness.    DETAILED DESCRIPTION - An easily-bonding layer composition comprises crosslinked resin, polyisocyanate compound crosslinked with main ingredient, aggregation inhibiting agent, white pigment, silane coupling agent, and organometallic coordination compound. The aggregation inhibiting agent comprises colloidal silica. The content ratio of crosslinked main ingredient resin, polyisocyanate compound and white pigment is 0.1-25 %mass with respect to total content of composition. The ratio of isocyanate value of polyisocyanate compound and the hydroxy value of crosslinked main ingredient resin is 1-4.7. The easily-bonding layer composition forms a white easily bonding layer on the surface of the white back surface protection sheet for solar cell module. INDEPENDENT CLAIMS are included for the following:    (1) white back surface protection sheet;    (2) manufacture of white back surface protection sheet; and    (3) solar cell module.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of solar cell module.    Solar cell module (1)    Transparent front substrate (2)    Front side sealing material layer (3)    Solar cell element (4)    Back surface side sealing material layer (5)    White back surface protection sheet (6)