To provide a lubricating structure of a roller bearing capable of reducing the agitation resistance of a lubricating oil in a bearing, and capable of preventing the seizure of a component in the bearing.

In the lubricating structure 20 of the roller bearing comprising an outer ring 21, an inner ring 22, a conical roller 23, and a retainer 24, the lubricating oil is supplied from one side in the axial direction into the bearing inside 25 demarcated between the outer ring 21 and the inner ring 22. and an annular shielding part 31 arranged in one side in the axial direction for the bearing inside 25 is provided to cover the end surface of the conical roller 23. The shielding part 31 has an annular wall 32 of a conical roller 23 side forming a first clearance 36 between the inner ring 22 and thereof, an annular wall 33 forming a second clearance 37 between the inner ring 22 and thereof separating from the annular wall 32 in the axial direction, and a cylindrical wall 34 communicating with both the clearances between the first clearance 36 and the second clearance 37, and forming a through-hole 34c opening to a radially outward side.