Formations of spatiotemporal patterns in nonlinear chemical reactions have attracted a lot of attentions from the viewpoint of dynamic self-organization in molecular systems. It is now widely known that such spatiotemporal patterns can also be observed in electrochemical systems. The electrochemical system has advantages for the study of the dynamic spatiotemporal patterns: (1) the distance from the equilibrium can be tuned continuously and reversibly by simply changing the electrode potential, (2) the diffusion processes can be flexibly controlled by tuning the structure of the electrochemical cell, and (3) the mode of the spatiotemporal patterns can be tuned easily by changing the geometrical arrangements of the electrodes and the applied potential or current. Here we review experimental and theoretical studies on the spatiotemporal patterns formed at electrode surfaces, by taking electrochemical oscillation during H₂O₂ reduction on Pt electrode as a representative example.