Water distribution in a three-cell stack was investigated. The water at cathode was collected in a liquid state directly. The water collection at cathode decreased with the increase of reactant supply. The liquid water was transported to the anode directly by hydrophilic fiberglass colligations, and this water amount increased with the increase of reactant supply. The water collected at cathode and the water transported to anode can achieve equilibrium by controlling the reactant operation conditions. The reactant circulation exhibited the benefit to improve the water distribution of stack.