Countertransport of ions is defined as the transport of an ion against its own concentration gradient driven by the third driving electrolyte added to the systems. The simulations and the experiments presented show that in the systems that consist of NaCl, KCl, and CaCl7 solutions divided by a bipolar membrane, there are two types of the countertransport of K+ and Ca2+ ions: forward countertransport (the countertransport in the direction of the concentration gradient of the driving electrolyte, NaCl) and backward countertransport (the countertransport in the direction opposite to the concentration gradient). In the system where the negatively charged layer of the membrane contacts the solution at the high-concentration side of NaCl, the forward countertransport occurs, and the membrane has permselectivity for univalent ions. In the system where the positively charged layer contacts the solution at the high-concentration side, the mode of the countertransport depends on the charge density ratio of the two charged layers.