The first porous molecular conductor (PMC), which exhibits porosity, a through-space conduction pathway and rich charge carriers (electrons), was prepared through electrocrystallization from Cd2+ and N,N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxdiimide (NDI-py). [Cd (NDI-py) (OH2)(4)] (NO3)(1.3 +/- 0.1)center dot nD MA (PMC-1) was assembled by pi-pi. stacking among one-dimensional (1D) linear coordination polymers. The NDI cores were partially reduced into radical anions to form conductive pi-stacked columns, yielding (1.0-3.3) X 10(-3) S cm(-1) at room temperature. Moreover, the electrical conductivity was significantly enhanced by removing the solvent molecules from PMC-1, indicating that PMCs are promising as molecule-responsive conductive materials.