Abstract: The formation of island arc (800-625 Ma.) on the northern part of the Gondwana land (Supercontinent) is accepted to be the begining phase in the geological evolution of Turkey. The rifting of the supercontinent and its breaking apart (625-555 Ma.) gave riseto the separation of the basement of the Pan African fragment-accepted to be the naclcous of the Anatolian microcontinent-from the northern part of the Gondwana land. Synorogenic sedimentation in the marginal basins (back-arc basin) (550-500 Ma.), orogenicmet amorphism (-500 Ma.), rise of the Anatolian microcontinent (500-470 Ma.) and intrusion of the collisional granitoids (470-450Ma.) are the most important phases in the geological evolution. Other important events at the end of Early Paleozoic can be cited asglaciation of the Gondwana land (450 Ma.). Toridya rise (440 Ma.), formation of glacial conglomerates and post glacial transgression (440-420 Ma.) and passage to the Anatolian carbonate platform (400 Ma.).