To solve an inconvenience that an intermediate flange formed between raceway surfaces of an inner ring and a roller are interfered in a midway of assembling of a two-split type self-aligning roller bearing.

In the two-split type self-aligning roller bearing, an inner ring 3 and an outer ring 6 two-split to an upper and lower part are assembled to the inside of a bearing box 1 divided to two upper and lower parts. A double- row roller and cage assembly 7 divided to two upper and lower parts is interposed between these inner ring 3 and outer ring 6. Tightening rings 8, 8' divided to two upper and lower parts are engaged with an outer diameter surface of both axial ends of the inner ring 3 to tighten the inner ring 3. The upper and lower divided bodies of the bearing box 1 are integrally bonded by a tightening member. A relief part 32 is provided at both sides of a tip end surface of an intermediate flange 10 formed between the raceway surfaces 4, 4 of the inner ring 3. A corner part of the rollers 23, 23 is abutted to the relief part 32 at the time of assembling and the rollers 23, 23 are outwardly moved to prevent an interference.