The paper presents the results of paleomagnetic studies of Cambrian islands arc system of Western Sayan - a central part of the Altai-Sayan fold area. Reconstruction of the Western Sayan Iceland Arc system is based on the new paleomagnetic data. This system, trending east-west, was formed in the Vendian - Early Cambrian on the oceanic crust, far off the margin of the Siberian Continent. By the Middle Cambrian, Sayan Island Arc moved southward (in ancient coordinates) towards and collided with the Siberian Continent.