Abstract: An object of the present invention is to provide a modified polyolefin resin composition having a high polyethylene content and exhibiting a good balance between a low-temperature stability and an adhesion to a polyethylene substrate and a metal. The present invention provides a modified polyolefin resin that is a graft-modified product in which a component (A) that is a polyolefin resin having an ethylene structural unit content of 50% or more by mole is modified with a component (B) that is an ?,?-unsaturated carboxylic acid or an anhydride thereof and a component (C) that is a (meth)acrylate ester represented by the following general formula (I), and an extrapolated melting end temperature (Tem) of the modified polyolefin resin measured in accordance with JIS K7121-1987 using a differential scanning calorimeter at a temperature raising rate of 10° C./minute is 58° C. or lower.