Abstract: A mortar grout splice sleeve (1) for reinforcing bars has a tubular metal shell (2) formed in both end portions (3) thereof with opposite openings (4) through which reinforcing bars (15) are inserted, and an annular seal (10) mounted in each of the end portions (3). The shell is formed in an tubular portion of thereof with a grout port (5) through which mortar (16) is injected into the shell. The seal (10) has a central bore (17) to be slidably fitted on the reinforcing bar (15). The seal (10) has an external circumference (11) tapered toward the shell (2) for fitting engagement with an inward tapered internal circumference (9) formed in the end portion (3) of the shell (2).