The reaction of pyridine‐2,3‐dicarboxylic acid (2,3‐pydcH2) with CuI and Ln2O3 under hydrothermal conditions generated a series of new one‐, two‐, and three‐dimensional coordination polymers, namely, {[Cu3Ln2(2,3‐pydc)6(H2O)12]·12H2O}n [Ln = La(1), Nd(2)], {[Cu3Ln2(2,3‐pydc)6(H2O)8]·6H2O}n [Ln = Sm(3), Gd(4)], and {[Cu3Ln2(2,3‐pydc)6(H2O)10]·10H2O}n [Ln = Tb(5), Ho(6), Er(7), Yb(8), Lu(9)]. The results show that compounds 1 and 2 (type I structure) are 1‐D Cu‐4f rhombic lattice chains that are formed through assembly of two building block units Cu3(pydc)6 and Ln(H2O)6. Compounds 3–4 (type II structure) are 2‐D layers that are constructed from building block units [Cu(pydc)2(H2O)2] μ2‐bridging adjacent 1‐D rhombic lattice chains –[(Cu2(pydc)4)‐(La(H2O)4)]n–. Complexes 5–9 (type III structure) are also isomorphous and have the same 3‐D network structures with 1‐D channels along the c axis, and are formed by assembly of building block units Cu3(pydc)6 with Ln(H2O)5. The progressive structural variation from the 1‐D chains 1–2 to 2‐D layers 3–4 and to 3‐D frameworks 5–9 is attributed to the lanthanide contraction effect and to the different coordination modes of 2,3‐pydc2–. The N2 gas adsorption and fluorescent properties of the partial complexes were also investigated.