Factor analysis is used to evaluate relationships among inorganic ions to provide a qualitative determination of the kind of ion sources Spanish wet deposition. This procedure identifies four factors: sea, soil, aerosol, and industrial. The factor that reproduces a larger fraction of the variance is the soil or soil/aerosol and the factor reproducing a lower fraction of the variance is the industrial. The conditional probability function (CPF) <Ashbaugh et al., 1985> is used to identify possible sources for each ion, in geographical terms. The Mediterranean region is the most important source of inorganic ions and the British Isles the single source, although intermediate, of acid rain. ¿ American Geophysical Union 1996