An imaging lens module includes a plastic lens barrel, a first optical element assembly and a second optical element assembly, wherein both of the first optical element assembly and the second optical element assembly are disposed in the plastic lens barrel. The plastic lens barrel includes a first inner annular surface and a second inner annular surface. The first inner annular surface forms a first receiving space. The second inner annular surface forms a second receiving space. The first optical element assembly is disposed in the first receiving space and includes a plurality of optical lens elements and a first retainer. The second optical element assembly is disposed in the second receiving space and includes a first light blocking sheet and a second retainer.