Dynamic behavior of the segmented-in-series tubular solid oxide fuel cell upon discharge was investigated. The cell performance decreased initially at 900 degrees C, accompanied by the increase of ohmic resistance. Lower partial pressure of oxygen in the cathode resulted in a more severe decrease, whereas the gas displacement in the anode compartment did not induce such behavior. As the current was cut off, the ohmic resistance rapidly recovered toward the starting value before current load. The possible origin for this increase-recovery behavior of the ohmic resistance has been discussed based on the evaluation of oxygen partial pressure at the cathode/electrolyte interface and element interdiffusion between cathode and electrolyte. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.099203jes] All rights reserved.