It is suggested that the Ordovician faunal provinces largely represent climatic zones, and the biological and lithological argument for and against this hypotesis are discussed. The pattern of climatic zones obtained indicate that 1) that Eur-Africa and the Americas have drifted 30--40° apart in an E-W direction since the Ordovician, but the evidence for this is not conclusive. 2) that one of the poles was in or just W. of Central Africa. Both of these features are supported by paleomagnetic studies. It is suggested that polar ice-caps existed during the Ordovician, and that the dose correlation of the climatic changes, with faunal migrations and transgressions-regression might be used for long distance correlations. The correlation between climatic changes and orogenies could be observed, but it is not very good, and there is no good correlation between climatic changes and volcanic activity in the Ordovician.