To provide a seam felt for papermaking capable of ensuring a sufficient thickness under compression in a pressing step and composed so as not to make the degree of collapsibility in a joined part extremely different from that of a ground part.

This seam felt has a ground fabric woven by using warp yarns on a paper machine as yarns to be beaten on a loom. Furthermore, the seam felt has a first and second warp yarns 3 and 4 formed of outer yarns to be beaten and a third and a fourth yarns 5 and 6 formed of inner yarns to be beaten. Joined loops 7 and 8 in one row are formed at both ends in either one or both turned back parts of the first and second warp yarns 3 and 4 and the third and fourth yarns 5 and 6. The first and third warp yarns 3 and 5 on the side of a paper-forming surface 9 in the first to the fourth warp yarns 3 to 6 are entangled with first weft yarns 10 and second weft yarns 11 superimposing on the first weft yarns 10 in the thickness direction are entangled with the second and fourth warp yarns 4 and 6 on the side opposite to the paper- forming surface 9.