Two proton-conductive and phosphorescent porous coordination polymers, La 3 -[H 5.5 RuP] 2 and Pr 3 -[H 5.5 RuP] 2 (H 12 RuP = [Ru­(H4dpbpy)3]2+, H4dpbpy = 2,2′-bipyridine-4,4′-bis­(phosphonic acid), composed of Ru­(bpy)3-type metalloligands (bpy = 2,2′-bipyridine) functionalized with six phosphonate groups and lanthanide cations (Ln3+ = La3+ or Pr3+) were successfully synthesized. X-ray diffraction studies revealed that six to seven protons of the H 12 RuP metalloligand were removed in the coordination polymerization reaction to form the porous coordination framework (Ln 3 -[H 5.5 RuP] 2 ) with Ln3+ cations (Ln3+ = La3+ or Pr3+). Although their porous structures collapsed on the removal of water molecules from the porous channels, the original porous structures were reconstructed by water adsorption. Interestingly, the triplet metal-to-ligand charge-transfer (3MLCT) emission of Ln 3 -[H 5.5 RuP] 2 was blue-shifted on increasing the relative humidity (RH) in the low RH region, whereas the inverse red shift was observed in the high RH region, resulting in the highest-energy 3MLCT emission at medium RH. The origin of this two-step vapochromic luminescence (that is, the blue and red shifts of the 3MLCT emission) is ascribable to the water-adsorption-triggered reconstruction of the porous structure and the proton release from the H 5.5 RuP metalloligand to the water filled channels, respectively. The proton conductivity of Ln 3 -[H 5.5 RuP] 2 is about 1000-times higher at 20% RH and 10-times higher at 95% RH than that of the carboxylate analog, La 7 -[RuC] 4 (H 6 RuC = [Ru­(H2dcbpy)3]2+; H2dcbpy = 2,2′-bipyridine-4,4′-bis­(carboxylic acid)), probably because of the highly acidic phosphonic acid groups.