A method for characterization of normally consolidated and overconsolidated clay subjected to undrained constant shear strain amplitude cyclic loading is presented and verified. The method is based on laboratory evidence that shows that clays exhibiting static normalized behavior with respect to the vertical consolidation stress, i.e., along the lines of the SHANSEP method, also exhibit a similar cyclic normalized behavior. The method is illustrated by cyclic results obtained on an offshore clay for the range of overconsolidation ratio (OCR) from 1 to 4, and is verified by predicting the initial backbone curve, cyclic stiffness degradation, and pore pressure variation for the same clay for OCR = 1.4. The predicted behavior for OCR = 1.4 successfully describes the corresponding laboratory results. Also, very consistent relationships between cyclic shear strain and other cyclic parameters obtained by means of cyclic strain-controlled testing in this and other similar studies confirm that the cyclic shear strain is probably the most fundamental parameter governing the undrained cyclic behavior of clay.Key words: clay, laboratory test, model, ocean soil, overconsolidation, soil dynamics, repeated loading, simple shear test.