The object of this research is to evaluate the Longshore Sediment Transport Capacity (LST) along the Catalan coast. The LST of a stretch of coast depends on its morphology, the characteristics of the sediment that forms the stretch and the characteristics of the waves that break over it. Taking this in account, many models have been developed in order to estimate LST, giving as a result several formulas. In this first chapter are revised and described the most widely used of them. The objective is to give an idea about the process of obtaining these formulas and to explain the influence of which parameters is considered in each formula. In the following chapters, some of the formulas will be applied to the stretches of beach of the Catalan coast. In that sense it is necessary to know which parameters are the most important to apply the formulas and to obtain them among the available data that has been collected along the Catalan coast up to day.