A series of pyrazole-bridged heterometallic 3d–4f complexes, [CuDy(ipdc) 2 (H 2 O) 4 ]·(2H 2 O)(H 3 O + ) (1) and [CuLn(pdc)(ipdc)(H 2 O) 4 ]·H 3 O + (Ln=Ho (2), Er (3), Yb (4); H 3 ipdc=4-iodo-3,5-pyrazoledicarboxylic acid; H 3 pdc=3,5-pyrazoledicarboxylic acid), {[Cu 3 Ln 4 (ipdc) 6 (H 2 O) 16 ]·xH 2 O} n (Ln=Sm (5), x=8.5; Ln=Eu (6), x=7; Ln=Gd (7), Tb (8), x=9), have been synthesized and structurally characterized. Ligand H 3 ipdc was in situ obtained by iodination of ligand H 3 pdc. Complexes 1–4 are pyrazole-bridged heterometallic dinuclear complexes, and 2–4 are isostructural. Complexes 5–8 are isostructural and comprised of an unusual infinite one-dimensional tape-like chain based on pyrazole-bridged heterometallic dinuclear units. The magnetic properties of compounds 1–4, 7 and 8 have been investigated through the magnetic measurement over the temperature range of 1.8–300K.