The reactions of porous two-dimensional copper dicarboxylates (copper fumarate, copper terephthalate, copper styrene dicarboxylate, and copper 4,4'-biphenyl dicarboxylate) with triethylenediamine as a pillar ligand yielded porous three-dimensional coordination polymers. The characterization by gas adsorption indicated that these coordination polymers have uniform micropores, high porosities, and gas adsorption capacities. These properties depend on the kind of dicarboxylate, and by changing it, the porosity and the pore size of the polymer can be controlled. The measurements of methane adsorption isotherms revealed that all coordination polymers have methane adsorption capacities, and especially, polymers synthesized from copper styrene dicarboxylate and copper 4,4'-biphenyl dicarboxylate, which have ideal pore sizes and distributions fur methane adsorption, have higher methane adsorption capacities than that of the theoretical maximum for activated carbon.