Transport loss characteristics of polygonal assemblies of coated conductors with textured-metal substrate were studied. Coated conductors using two types of textured-metal tape as their substrate were prepared for the experiments: a Ni alloy substrate and a clad-type substrate with reduced magnetism. First, the transport losses of hexagonal assemblies of coated conductors with non-magnetic substrate were measured where the textured-metal tapes were under-lied or over-lied on the coated conductors to simulate the coated conductors fabricated with these textured-metal substrates. The over-lied Ni alloy tapes affect transport loss characteristics substantially; the over-lied or under-lied clad tapes do not substantially affect them. Next, two types of hexagonal assemblies were made using coated conductors fabricated with the textured-metal substrates: the substrates were placed inside in one of them, and they were placed outside in the other. In case of the coated conductors fabricated with the Ni alloy substrate, the measured transport loss of the latter was much larger than that of the former, because the substrates placed outside were exposed to the magnetic field generated around the assembled coated conductors. The measured transport losses reasonably agree with the numerically-calculated ones. In case of the coated conductors fabricated with the clad substrate, the difference between the transport losses of the two types of the assemblies is much smaller; the influence of the magnetism of the clad substrate on AC losses is reasonably small.