Abstract　 　　
Magnetic fields are thought to play an important role in the evolution of classical T Tauri stars, directly controlling the accretion processes from the the circumstellar disks to the central stars. Understanding how magnetic fields affect the evolution and subsequent dispersal of the disks is essential to our understanding of planet formation. I will discuss how we can detect magnetic fields on the young stars and what observations tell us about the origins and evolution of their magnetic properties.