In order to evaluate the local pressure drop in the gas channel of a polymer electrolyte fuel cell (PEFC), liquid droplet were modeled as two shapes by using neutron radiography. Based on the models, local pressure drop caused by a droplet were evaluated by CFD as a function of the water saturation, and it was applied to a network model calculating gas velocity distributions in the PEFC. Two dimensional water distributions measured by neutron radiography were applied to the network model, and the pressure drop between inlet and outlet of the gas channel were good agreement with the experimental results.