Electrochemical characterizations of chromatography paper-based electrochemical sensors are presented by means of chronoamperometory (CA), cyclicvoltammetry (CV), and impedance (IMP) measurement. Samples with co-planar electrodes with dropped solution, height-limited solution, and solution within a sheet of chromatography paper, were tested. It was found that the height limitation, reduction of diffusion coefficient, and thin solution layer between paper and chip substrate can impact the shapes of CA and CV, which was confirmed by computer simulations. It was also found that solution resistance due to ion conduction in paper sensor will be reduced because of ion conductivity reduction.