A power transmission chain (1) includes connection members (3; 3A; 4) flexibly connecting corresponding links (2) of a plurality of link rows (52; 52; 53). The connection members (3; 3A; 4) include a first power transmission member (3; 3A) and a second power transmission member (4). The chain (1) includes a module (40; 40A) as a unit element. A moving locus of a contact part (T1; T1A) between the corresponding first and second power transmission members conjunction with flexure between the links (2) defines prescribed curve. The positions of a gravity center (GC; GCA) of the contact part (T1; T1A) and the module (40; 40A) in the chain straight area are space apart by a prescribed distance from each other with respect to an orthogonal direction (V) perpendicular to both a chain advancing direction (X) and a chain width direction (W). The prescribed distance is not more than 20% of overall length of the module (40) with respect to the orthogonal direction (V)