North America possesses the biggest single potash deposits and half of the potash reserves in the world. Here we briefly summarize the major tectonic elements and geological evolution of North America, then reviewed the cratonic platform sequences in detail. By relating the potash deposits with the geological settings, we know that potash best developed in undercompensated intracratonic platform basins, and could also developed in graben or rifted marginal cratonic basins. Potash occurred in the last marine platform sequences (Kaskaskia), and the Absaroka sequences represented transition from marine facies to terrestrial facies. As to foreland basins, no potash found there yet. The extensive deposition of potash salts in North America in Paleozoic Era was associated closely with the position of paleoequator. Potash deposition was controlled by the combination of tectonic, depositional and climatic conditions, so the prospect of potash should follow these clues.