A Ca2+ porous coordination polymer with 1D channels was functionalized by the postsynthesis addition of LiCl to enhance the H+ conductivity. The compound showed over 10鈥? S cm鈥? at 25 掳C and 20% relative humidity. Pulse-field gradient NMR elucidated that the fast H+ conductivity was achieved by the support of Li+ ion movements in the channel.